HomeMy WebLinkAbout20091480.tiffAUTHORIZATION TO DISCHARGE UNDER THE
COLORADO DISCHARGE PERMIT SYSTEM
In compliance with the provisions of the Colorado Water Quality Control Act, (25-8-101 et seq., CRS, 1973 as amended),
for both discharges to surface and ground waters, and the Federal Water Pollution Control Act, as amended (33 U.S.C.
1251 et seq.; the "Act"), for discharges to surface waters only, the
Town of Berthoud
is authorized to discharge from the Town's wastewater treatment plant located at SW 1/4, Section 19, T4N, R68W, 6th
P.M.; 20213 WCR #1, Berthoud, CO; 40°17'00" N, 105°04'00" W
to the Little Thompson River
in accordance with effluent limitations, monitoring requirements and other conditions set forth in Parts I and II hereof.
All discharges authorized herein shall be consistent with the terms and conditions of this permit.
The applicant may demand an adjudicatory hearing within thirty (30) days of the date of issuance of the final permit
determination, per the Colorado State Discharge Permit System Regulation 61.7O). Should the applicant choose to
contest any of the effluent limitations, monitoring requirements or other conditions contained herein, the applicant must
comply with Section 24-4-104 CRS 1973 and the Colorado State Discharge Permit System Regulations. Failure to
contest any such effluent limitation, monitoring requirement, or other condition, constitutes consent to the condition by
the applicant.
This permit and the authorization to discharge shall expire at midnight,
Issued and Signed this day of
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Janet Kieler, Permits Section Manager
Water Quality Control Division
74-7
blCc KQCI eLD
2009-1480
Town of Berthoud WWTF Water Quality Assessment CO -0046663
APPENDIX A
Water Quality Assessment
the Little Thompson River
Town of Berthoud WWTF
Table of Contents
I. WATER QUALITY ASSESSMENT SUMMARY 2
II. INTRODUCTION 3
III. WATER QUALITY STANDARDS 4
Narrative Standards 4
Standards for Organic Parameters and Radionuclides 5
Salinity and Phosphorus 6
Temperature 6
Segment Specific Numeric Standard 7
Table Value Standards and Hardness Calculations 8
Regulation 93 — 303(d) List and Total Maximum Daily Loads 10
IV. RECEIVING STREAM INFORMATION 11
Low Flow Analysis 11
Mixing Zones 11
Ambient Water Quality 12
V. FACILITY INFORMATION AND POLLUTANTS EVALUATED 12
Facility Information 12
Pollutants of Concern 13
VI. DETERMINATION OF WATER QUALITY BASED EFFLUENT LIMITATIONS (WQBELS) 14
Technical Information 14
Calculation of WQBELs 15
VII. ANTIDEGRADATION EVALUATION 17
VIII. REFERENCES 18
Appendix A (WQA V 7.0)
Page 1 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
I. Water Quality Assessment Summary
Table A-1 includes summary information related to this WQA. This summary table includes key
regulatory starting points used in development of the WQA such as: receiving stream information;
threatened and endangered species; 303(d) and 305(b) listings; low flow and facility flow
summaries; and a list of parameters evaluated.
Table A-1
WQA Summary
Facility Information
Facility Name
Permit Number .
Design Flow
(max 30 -day.
aye, MGD)
: Design Flow
(max 3O -day
aye, CFS)
Fl. Town of Berthoud WWTF
CO -0046663
2.0
3.1
Receiving Stream Information:.
Receiving Stream.Name, E.:::.:
:..:.
Segment ID
Designation:::::::
:.. ...:...... .
' eation(sj .. .
S 1. Little Thompson
River
COSPBT09
Use Protected
Aquatic Life Warm 2,
Recreation Class la,
Agriculture
Low Flows (cfs)
1E3 (1 -day)
7E3 (7 -day)
30E3 (30 -day)
Ratio of 30E3 to the
Design Flow (cfs)
S 1.0
0
0
1'1: 0
Regulatory Information
T&E
Species
303(d)
(Reg 93)
TMDL
Status
305(b)
(Reg 94)
Temporary
Modification(s)
Control
Regulation
No
Cu, Se, E.
coli,
Aquatic
Life Use
Medium
(Cu, Aq
Life Use)
High (E.
Coli)
Low (Se)
None
Temporary
modifications:
NH3(ac/ch)=TVS
(old)(Type i).
Expiration date
of 12/31/2011.
None
Pollutants Evaluated
Fl: Ammonia, E. Coli, Metals, TRC, Temperature
Appendix A (WQA V 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
H. Introduction
The water quality assessment (WQA) of the Little Thompson River near the Town's Wastewater
Treatment Facility (WWTF), located in Weld County, is intended to determine the assimilative
capacities available for pollutants found to be of concern. This WQA describes how the water
quality based effluent limits (WQBELs) are developed. These parameters may or may not appear in
the permit with limitations or monitoring requirements, subject to other determinations such as
reasonable potential analysis, evaluation of federal effluent limitation guidelines, implementation of
state -based technology based limits, mixing zone analyses, 303(d) listings, threatened and
endangered species listing, or other requirements as discussed in the permit rationale. Figure A-1
contains a map of the study area evaluated as part of this WQA.
FIGURE A-1
CAB
Ric ereatdi Siatirm 161
Bath¢udd P
Ewrytl' NJ W to9ca'. czteptym P
StudyArea
Appendix A (WQA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
The Town of Berthoud WWTF discharges to the Little Thompson River, which is in the Water Body
Identification (WBID) stream segment COSPBT09. This means the South Platte Basin, Big Thompson
River Sub -basin, Stream Segment 09. This segment is composed of the "Mainstem of the Little
Thompson River from the Culver Ditch diversion to the confluence with the Big Thompson River.".
Stream segment COSPBT09 is classified for Warm Water Aquatic Life Class 2, Class la Existing
Primary Contact Recreation and Agriculture.
Information used in this assessment includes data gathered from the Town of Berthoud WWTF, the
Division, the Colorado Division of Water Resources (DWR), Riverwatch, the U.S. Environmental
Protection Agency (EPA), the U.S. Geological Survey (USGS), the U.S. Census Bureau and previous
communications with the local water commissioner. The data used in the assessment consist of the best
information available at the time of preparation of this WQA/PELs analysis.
III. Water Quality Standards
Narrative Standards
Narrative Statewide Basic Standards have been developed in Section 31.11(1) of the regulations, and
apply to any pollutant of concern, even where there is no numeric standard for that pollutant. Waters of
the state shall be free from substances attributable to human -caused point source or nonpoint source
discharges in amounts, concentrations or combinations which:
for all surface waters except wetlands;
(i) can settle to form bottom deposits detrimental to the beneficial uses. Depositions are stream
bottom buildup of materials which include but are not limited to anaerobic sludge, mine slurry or
tailings, silt, or mud; or
(ii) form floating debris, scum, or other surface materials sufficient to harm existing beneficial uses;
or
(iii) produce color, odor, or other conditions in such a degree as to create a nuisance or harm existing
beneficial uses or impart any undesirable taste to significant edible aquatic species or to the water; or
(iv) are harmful to the beneficial uses or toxic to humans, animals, plants, or aquatic life; or
(v) produce a predominance of undesirable aquatic life; or
(vi) cause a film on the surface or produce a deposit on shorelines; and
for surface waters in wetlands;
(i) produce color, odor, changes in pH, or other conditions in such a degree as to create a nuisance or
harm water quality dependent functions or impart any undesirable taste to significant edible aquatic
species of the wetland; or
(ii) are toxic to humans, animals, plants, or aquatic life of the wetland.
In order to protect the Basic Standards in waters of the state, effluent limitations and/or monitoring
requirements for any parameter of concern could be put in CDPS discharge permits.
Appendix A (WQA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
Standards for Organic Parameters and Radionuclides
Radionuclides: Statewide Basic Standards have been developed in Section 31.11(2) and (3) of The
Basic Standards and Methodologies for Surface Water to protect the waters of the state from
radionuclides and organic chemicals.
In no case shall radioactive materials in surface waters be increased by any cause attributable to
municipal, industrial, or agricultural practices or discharges to as to exceed the following levels,
unless alternative site -specific standards have been adopted. Standards for radionuclides are shown
in Table A-2.
Table A-2
Radionuclide Standards
Parameter
Picocuries per Liter
Americium 241*
0.15
Cesium 134
80
Plutonium 239, and 240*
0.15
Radium 226 and 228*
5
Strontium 90*
8
Thorium 230 and 232*
60
Tritium
20,000
*Radionuclide samples for these materials should be analyzed using unfiltered (total) samples.
These Human Health based standards are 30 -day average values for both plutonium and
americium.
Organics: The organic pollutant standards contained in the Basic Standards for Organic Chemicals
Table are applicable to all surface waters of the state for the corresponding use classifications, unless
alternative site -specific standards have been adopted. These standards have been adopted as
"interim standards" and will remain in effect until alternative permanent standards are adopted by
the Commission. These interim standards shall not be considered final or permanent standards
subject to antibacksliding or downgrading restrictions. Although not reproduced in this WQA, the
specific standards for organic chemicals can be found in Regulation 31.11(3).
In order to protect the Basic Standards in waters of the state, effluent limitations and/or monitoring
requirements for radionuclides, organics, or any other parameter of concern could be put in CDPS
discharge permits.
The aquatic life standards apply to all stream segments that are classified for aquatic life. The water
supply standards apply only to those segments that are classified for water supply. The water + fish
standards apply to those segments that have a Class 1 aquatic life and a water supply classification. The
fish ingestion standards apply to Class 1 aquatic life segments that do not have a water supply
designation. The water + fish and the fish ingestion standards may also apply to Class 2 aquatic life
segments, where fish of a catchable size and which are normally consumed are present, and where
fishing occurs on a regular basis.
Appendix A (wQA V 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
Because the the Little Thompson River is classified for Class 2 aquatic life, without a water supply
designation, the aquatic life standards apply to this discharge.
Salinity and Phosphorus
Phosphorus: Regulations 71, 72, 73 and 74, for Dillon Reservoir Watershed, Cherry Creek Reservoir
Watershed, Chatfield Reservoir Watershed and the Bear Creek Watershed, contain requirements for
phosphorus concentrations and phosphorus annual loadings for point source dischargers. If a facility
discharges to one of these watersheds, a phosphorus allocation may be necessary, and limitations and
annual loadings may be added to a permit.
Salinity: Regulation 61.8(2)0) contains requirements regarding salinity for any discharges to the
Colorado River Watershed. For industrial dischargers this is a no -salt discharge requirement. However,
the regulation states that this requirement may be waived where the salt load reaching the mainstem of
the Colorado River is less than 1 ton per day, or less than 366 tons per year. The Division may permit
the discharge of salt upon a satisfactory demonstration that it is not practicable to prevent the discharge
of all salt. See Regulation 61.8(2)(l)(i)(A)(1) for more information regarding this demonstration.
For municipal dischargers, an incremental increase of 400 mg/1 above the flow weighted averaged
salinity of the intake water supply is allowed. This may be waived where the salt load reaching the
mainstem of the Colorado River is less than 1 ton per day, or less than 366 tons per year. The Division
may permit the discharge of salt in excess of the 400 mg/1 incremental increase, upon a satisfactory
demonstration that it is not practicable to attain this limit. See Regulation 61.8(2)(1)(vi)(A)(1) for more
information regarding this demonstration.
Regulation 75 contains requirements for the release of water from Cheraw Lake. Any entity releasing
water from Cheraw Lake must ensure that either: 1) the water has a TDS concentration less than or equal
to 4300 mg/1, or 2) that an adequate quantity of water of less saline nature can be supplied for dilution
purposes such that a salinity level of 4300 ppm, measured as TDS, can be maintained in Horse Creek
immediately above the first diversion below the confluence with the Cheraw Lake outlet channel.
In addition, the Division's policy, Implementing Narrative Standards in Discharge Permits for the
Protection of Irrigated Crops, may be applied to discharges where an agricultural water intake exists
downstream of a discharge point. Limitations for electrical conductivity, sodium absorption ratio, or
sodium, may be applied in accordance with this policy.
Temperature
All waters of the South Platte, Laramie, Republican and Smoky Hill River Basins are subject to the
following standard for temperature. (Discharges regulated by permits, which are within the permit
limitations, shall not be subject to enforcement proceedings under this standard). Temperature shall
maintain a normal pattern of diurnal and seasonal fluctuations with no abrupt changes and shall have
no increase in temperature of a magnitude, rate, and duration deemed deleterious to the resident
aquatic life. This standard shall not be interpreted or applied in a manner inconsistent with section
25-8-104, C.R.S. Effective until December 31, 2009: Segments or portions of segments that are first,
Appendix A (WQA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
second or third order streams above 7000 feet elevation and classified Aquatic Life cold 1 or 2 shall
have a chronic temperature standard of 17 °C (MWAT) with no acute standard. The following waters
designated as Gold Medal fisheries by the Colorado Wildlife Commission shall have a chronic
temperature standard of 18.2 °C (MWAT):
• South Platte River (rainbow and brown trout fishery, residual cutthroats) (A) From the
confluence of the Middle and South Forks of the South Platte downstream to the inlet of Spinney
Mountain Reservoir; (B) Middle fork from Highway 9 bridge downstream to the South Fork of the
South Platte; South fork above Antero Reservoir to Highway 285; (C) From the outlet of Spinney
Mountain Reservoir downstream to the inlet of the Elevenmile Canyon Reservoir; and
• Spinney Mountain Reservoir (rainbow and brown trout fishery, some Snake River cutthroat
trout) on the South Platte River, 5 miles upstream from Elevenmile Canyon Reservoir.
Other cold class 1 or 2 segments or portions of segments shall have a chronic temperature standard of 20
°C (MWAT) with no acute standard. Segments that are classified Aquatic Life warm 1 or 2 shall have a
chronic temperature standard of 30 °C (MWAT) with no acute standard.
Segment Specific Numeric Standards
Numeric standards are developed on a basin -specific basis and are adopted for particular stream
segments by the Water Quality Control Commission. To simplify the listing of the segment -specific
standards, many of the aquatic life standards arc contained in a table at the beginning of each chapter of
the regulations. The standards in Table A-3 have been assigned to stream segment COSPBT09 in
accordance with the Classifications and Numeric Standards, for South Platte River Basin, Laramie River
Basin, Republican River Basin, Smoky Hill River Basin.
Appendix A (WQA V 7.0)
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Town of Berthoud WWTF Water Quality Assessment
Table A-3
In -stream Standards for Stream Segment COSPBT09
Physical and Biological
Dissolved Oxygen (DO) = 5 mg/I, minimum
pH=6.5 - 9 su
Fecal Coliform chronic = 200 colonies/ 100 ml
E. coli chronic = 126 colonies/100 ml
CO -0046663
Temperature chronic (MWAT)=30 ° C
Inorganic
Total Ammonia acute and chronic =TVS
Unionized Amonia(acute and chronic) TVS(old) Expires 12/31/2011
Chlorine acute = 0.019 mg/I
Chlorine chronic = 0.011 mg/1
Free Cyanide acute = 0.005 mg/I
Sulfide chronic = 0.002 mg/1
Boron chronic = 0.75 mg/I
Nitrite acute = 0.5 mg/1
Metals ')
Total Recoverable Arsenic chronic = 100 µg/l
Dissolved Cadmium acute and chronic = TVS
Dissolved Trivalent Chromium acute and chronic = TVS
Dissolved Hexavalent Chromium acute and chronic = TVS
Dissolved Copper acute and chronic=TVS
Total Recoverable Iron chronic = 1000 µg/I
Dissolved Lead acute and chronic = TVS
Dissolved Manganese acute and chronic = TVS
Total Mercury chronic = 0.01 µg/1
Dissolved Nickel acute and chronic = TVS
Dissolved Selenium acute and chronic = TVS
Dissolved Silver acute and chronic = TVS
Dissolved Zinc acute and chronic = TVS
Table Value Standards and Hardness Calculations
Standards for metals are generally shown in the regulations as Table Value Standards (TVS), and these
often must be derived from equations that depend on the receiving stream hardness or species of fish
present; for ammonia, standards are discussed further in Section IV of this WQA. The Classification
and Numeric Standards documents for each basin include a specification for appropriate hardness values
to be used. Specifically, the regulations state that:
The hardness values used in calculating the appropriate metal standard should be based on
the lower 95% confidence limit of the mean hardness value at the periodic low flow
criteria as determined from a regression analysis of site -specific data. Where insufficient
site -specific data exists to define the mean hardness value at the periodic low flow criteria,
Appendix A (WQA V 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
representative regional data shall be used to perform the regression analysis. Where a
regression analysis is not appropriate, a site -specific method should be used.
Hardness data for the Little Thompson River near the point of discharge of the Town of Berthoud
WWTF were insufficient to conduct a regression analysis based on the low flow. Therefore, the
Division's alternative approach to calculating hardness was used, which involves computing a mean
hardness.
The mean hardness of the Little Thompson River was computed to be 820.2 mg/1 based on sampling
data from Riverwatch Station 161 (WCR 1) located on the Little Thompson River less than one mile
upstream of the Town of Berthoud WWTF. The Basic Standards and Methodologies for Surface Water
indicates that hardness must be capped at 400 mg/I when determining in -stream metal water quality
standards using the equations in the TVS. This maximum hardness value and the formulas contained in
the TVS were used to calculate the in -stream water quality standards for metals, with the results shown
in Table A-4.
Appendix A (W QA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment
Table A-4
TVS-Based Metals Water Quality Standards for CO -0046663
Based on the Table Value Standards Contained in the Colorado Department of Public Health and
Environment Water Quality Control Commission Regulation 38
Parameter
In -Stream Water
Quality Standard
TVS Formula:
Hardness (mg/l) as`CaCO3 = 400
Cadmiurrl, Dissolved
Acute
Chronic
19 tie
[1 . 13667-0.04 1841n(hardness)1[e (I I28(In(hardncs's))-3.6867)1
6.2 pg/I
(0.7852(In(hardncs's'))-2.715)]
[1.10167-0.041841n(hardncss)1[e
Trivalent Chromium,
Dissolved
Acute
1773 µg/1
e (0.819(In(hardness))+2.5736)
Chronic
231 µg/1
e (0.819pn(hardaess)) 03.5340)
Hexavalent Chromium,
Dissolved
Acute
16 µg/I
Numeric standards provided, formula not applicable
Chronic
11 µg/1
Numeric standards provided, formula not applicable
Copper, Dissolved
Acute
50 µg/1
e (0.9422(In(hardness))-1.7408)
Chronic
29 µg/1
e (0.8545(In(hardness))-1.7428)
Lead, Dissolved
Acute
281 µg/1
[1.46203-0.1457121n(hardness)][e(1.273(In(hardness))-1.46)1
Chronic
11 µg/1
[1.46203-0.'45712ln(hardness)l[e(1.273(In(hardness))-4.705)]
Manganese, Dissolved
Acute
4738 µg/1
e (0.3331(ln(hardncss))+6.4676)
Chronic
2618 µg/1
e (03331 (In(hardness))+5.8743)
Nickel, Dissolved
Acute
1513 µg/1
e (0.846(In(hardness))+2253)
Chronic
168 µg/1
e (0.846(In(hardncss))+0.0554)
Selenium, Dissolved
Acute
18.4 µg/1
Numeric standards provided, formula not applicable
Chronic
4.6 µg/1
Numeric standards provided, formula not applicable
Silver, Dissolved
Acute
22 µg/1
1/2 e (I,72(In(hardness))-6.52)
Chronic
3.5 µg/1
e (I.72(In(hardness))-9.06)
Zinc, Dissolved
Acute
379 µg/1
e (0.8473(In(hardness))+0.8618)
Chronic
382 ug/I
e (0.8473(In(hardness))+0.8699)
CO -0046663
Regulation 93 — 303(d) List and Total Maximum Daily Loads
This stream segment is on the 303(d) list of water quality impacted streams for Cu, Se, E. call and
Aquatic Life Use. According to Division standard procedure, the Division's Environmental Data Unit
investigates issues of water quality standard exceedances. For a receiving water placed on this list, the
Restoration and Protection Unit is tasked with developing the Total Maximum Daily Loads (TMDLs)
and the Waste Load Allocation (WLAs) to be distributed to the affected facilities. WLAs for Cu, Se, E.
colt and Aquatic Life Use have not yet been established and the allowable concentration calculated in
the following sections may change upon further evaluation by the Division.
Appendix A (wQA V 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
IV. Receiving Stream Information
Low Flow Analysis
The Colorado Regulations specify the use of low flow conditions when establishing water quality based
effluent limitations, specifically the acutc and chronic low flows. The acute low flow, referred to as
1E3, represents the one -day low flow recurring in a three-year interval, and is used in developing
limitations based on an acute standard. The 7 -day average low flow, 7E3, represents the seven-day
average low flow recurring in a 3 year interval, and is used in developing limitations based on a
Maximum Weekly Average Temperature standard (MWAT). The chronic low flow, 30E3, represents
the 30 -day average low flow recurring in a three-year interval, and is used in developing limitations
based on a chronic standard.
As flow data for the receiving stream is not available, the local water commissioner was contacted to
obtain an estimate of the low flow for this receiving water. According to discussions with the local
water commissioner, the Little Thompson River has a low flow of zero. For this analysis, low flows are
summarized in Table A-5.
Table A-5
Low Flows for the Little Thompson River at the Town of Berthoud WWTF
Low Flow.
(els)
Annual
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
I E3
Acute
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Chronic
0.00
0.00
0.00
coo
0.00
0.00
0.00
0.00
0.00
0.00
coo
o.00
0.00
30E3
Chronic
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
The ratio of the low flow of the Little Thompson River to the Town of Berthoud WWTF design flow is
0:1
Note that since the low flow has been determined to be zero, the ambient water quality discussion is
unnecessary and has therefore been deleted in this WQA. This is explained in more detail under the
Technical Information discussion in Section VI.
Mixing Zones
The amount of the available assimilative capacity (dilution) that may be used by the permittee for the
purposes of calculating the WQBELs may be limited in a permitting action based upon a mixing zone
analysis or other factor. These other factors that may reduce the amount of assimilative capacity
available in a permit are: presence of other dischargers in the vicinity; the presence of a water diversion
downstream of the discharge (in the mixing zone); the need to provide a zone of passage for aquatic life;
Appendix A (WQA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
the likelihood of bioaccumulation of toxins in fish or wildlife; habitat considerations such as fish
spawning or nursery areas; the presence of threatened and endangered species; potential for human
exposure through drinking water or recreation; the possibility that aquatic life will be attracted to the
effluent plume; the potential for adverse effects on groundwater; and the toxicity or persistence of the
substance discharged.
Unless a facility has performed a mixing zone study during the course of the previous permit, and a
decision has been made regarding the amount of the assimilative capacity that can be used by the
facility, the Division assumes that the full assimilative capacity can be allocated. Note that the review of
mixing study considerations, exemptions and perhaps performing a new mixing study (due to changes in
low flow, change in facility design flow, channel geomorphology or other reason) is evaluated in every
permit and permit renewal.
If a mixing zone study has been performed and a decision regarding the amount of available assimilative
capacity has been made, the Division may calculate the water quality based effluent limitations
(WQBELs) based on this available capacity. In addition, the amount of assimilative capacity may be
reduced by T&E implications.
Since the receiving stream has a zero low flow as calculated above, the WQBELs would be equal to the
WQS, and therefore consideration of full or reduced assimilative capacity is inconsequential.
Ambient Water Quality
The Division evaluates ambient water quality based on a variety of statistical methods as prescribed in
Section 31.8(2)(a)(i) and 31.8(2)(b)(i)(B) of the Colorado Department of Public Health and
Environment Water Quality Control Commission Regulation No. 3/, and as outlined in the Division's
Policy for Characterizing Ambient Water Quality for Use in Determining Water Quality Standards
Based Effluent Limits (WQP-19). The ambient water quality was not assessed for the Little Thompson
River because the background in -stream low flow condition is zero.
V. Facility Information and Pollutants Evaluated
Facility Information
The Town of Berthoud WWTF is located at SW 1/4, Section 19, T4N, R68W, 6th P.M.; 20213 WCR
#1, Berthoud, CO; 40°17'00" N, 105°04'00" Win Weld County. The current design capacity of the
facility is 2 MGD (3.lcfs). Wastewater treatment is accomplished using a mechanical wastewater
treatment process. The technical analyses that follow include assessments of the assimilative
capacity based on this design capacity.
An assessment of nearby facilities based on EPA's Permit Compliance System (PCS) database found 26
dischargers in the Weld County area. More than one-half of the facilities were discharging to another
watershed. Several facilities conducted construction -related operations (e.g., sand and gravel) and thus
had no pollutants of concern in common with the Town of Berthoud WWTF. Other facilities were
located more than twenty miles from the Town of Berthoud WWTF and thus were not considered. The
nearest dischargers were:
Appendix A (WQA v 7.0)
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Town of Berthoud WWTF Water Quality Assessment CO -0046663
River Glen Homeowners Association (CO -0029742) with a design flow of 0.029 MGD
discharges directly into Little Thompson River, approximately two miles upstream of the
confluence with No Name Creek.
• Berthoud Estates (COG582009), with design capacity of 0.052 MGD, and Vaquero Estates
(COG582032), with design capacity of 0.025 MGD, discharge to Dry Creek both at
approximately '/z mile upstream of the confluence of Dry Creek with Little Thompson River.
Due to the in -stream low flow of zero, the assimilative capacities during times of low flow are not
affected by nearby contributions. Therefore, modeling nearby facilities in conjunction with this facility
was not necessary.
Based on available information, there is no indication that non -point sources were a significant source of
pollutants of concern. Thus, non -point sources were not considered in this assessment.
Pollutants of Concern
Pollutants of concern may be determined by one or more of the following: facility type; effluent
characteristics and chemistry; effluent water quality data; receiving water quality; presence of federal
effluent limitation guidelines; or other information. Parameters evaluated in this WQA may or may not
appear in a permit with limitations or monitoring requirements, subject to other determinations such as a
reasonable potential analysis, mixing zone analyses, 303(d) listings, threatened and endangered species
listings or other requirement as discussed in a permit rationale.
The following parameters were identified by the Division as pollutants to be evaluated for this facility:
• Total Residual Chlorine
• E. coli
• Ammonia
• Temperature
• Metals and Cyanide
There are no site -specific in -stream water quality standards for BOD5 or CBOD5, TSS, percent
removal, and oil and grease for this receiving stream. Thus, assimilative capacities were not
determined for these parameters. The applicable limitations for these pollutants can be found in
Regulation No. 62 and will be applied in the permit for the WWTF.
It is the Division's standard procedure to consider metals and cyanide as potential pollutants of concern
for all major domestic WWTFs.
During assessment of the facility, nearby facilities, and receiving stream water quality, no additional
parameters were identified as pollutants of concern.
Appendix A (WQA v 7A)
Page 13 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
VI. Determination of Water Quality Based Effluent Limitations (WQBELs)
Technical Information
Note that the WQBELs developed in the following paragraphs, are calculations of what an effluent
limitation may be in a permit. The WQBELs for any given parameter, will be compared to other
potential limitations (federal Effluent Limitations Guidelines, State Effluent Limitations, or other
applicable limitation) and typically the more stringent limit is incorporated into a permit. If the WQBEL
is the more stringent limitation, incorporation into a permit is dependent upon a reasonable potential
analysis.
In -stream background data and low flows evaluated in Sections II and III are used to determine the
assimilative capacity of the Little Thompson River near the Town of Berthoud WWTF for pollutants of
concern, and to calculate the WQBELs. For all parameters except ammonia, it is the Division's
approach to calculate the WQBELs using the lowest of the monthly low flows (referred to as the annual
low flow) as determined in the low flow analysis. For ammonia, it is the standard procedure of the
Division to determine monthly WQBELs using the monthly low flows, as the regulations allow the use
of seasonal flows.
The Division's standard analysis consists of steady-state, mass -balance calculations for most pollutants
and modeling for pollutants such as ammonia. The mass -balance equation is used by the Division to
calculate the WQBELs, and accounts for the upstream concentration of a pollutant at the existing
quality, critical low flow (minimal dilution), effluent flow and the water quality standard. The mass -
balance equation is expressed as:
M3Q3- MIQI
M2=
Q2
Where,
Qi = Upstream low flow (1E3 or 30E3)
Q2 = Average daily effluent flow (design capacity)
Q3 = Downstream flow (Q1 + Q2)
M = In -stream background pollutant concentrations at the existing quality
M3 = Calculated WQBEL
M3 = Water Quality Standard, or other maximum allowable pollutant concentration
When Q7 equals zero, Q2 equals Q3, and the following results:
M2=M3
Because the low flow (Q1) for the Little Thompson River is zero, the WQBELs for the Little Thompson
River for the pollutants of concern are equal to the in -stream water quality standards.
A more detailed discussion of the technical analysis is provided in the pages that follow.
Appendix A (WQA V 7 0)
Page 14 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
Calculation of WQBELs
Where a WQBEL is calculated to be less than a standard the Division standard procedure is to allocate
the water quality standard to prevent further degradation of the receiving waters. The Division's
Environmental Data Unit investigates issues of water quality standard exceedances. This Unit is tasked
with determining if the exceedances are valid and placing the receiving stream on the Clean Water Act
Section 303(d) list of impaired waters, if appropriate. If the receiving water is placed on the State's
303(d) list, the Restoration and Protection Unit is tasked with developing the Total Maximum Daily
Loads (TMDLs) and the Waste Load Allocations (WLAs) to be distributed to the affected facilities.
Chlorine: The WQBELs for total residual chlorine were determined to equal the in -stream water quality
standards as shown in Table A-6.
Table A-6
Chlorine Assimilative Capacities
Parameter
r (cfs);;.
0.00
/1)
0.019
2 (mg/1)
0.019
Acute Chlorine
3.1
3.1
0
Chronic Chlorine
0.00
3.1
3.1
0
0.011
0.011
E. coli: Available studies indicate hat Escherichia coli (E. coli), which is a subset of fecal coliform, is a
better predictor of potential human health impacts from waterborne pathogens. The Water Qua ity
Control Commission is replacing all standards for fecal coliform with standards for E. coli. There are no
point sources discharging E. coli within one mile of the Town of Berthoud WWTF. Thus, WQBELs
were evaluated separately.
The WQBELs for E. coli were determined to equal the in -stream water quality standard as shown in
Table A-7.
Table A-7
K coli Assimilative Capacities
Para
eter
Q j (c
Qz (f
Q3 (els)
M r (4/100
ml)
126
M2 (#7190
ml)'
E. co 1
0.00
3.1
3.1
126
Temperature: The 7E3 is 0. For the purposes of this permitting action it is assumed that the
receiving water is effluent dependent at the location of the discharge. Therefore in accordance with
Regulation 31.14(14), no temperature limitations arc required.
Metals and Cyanide: Metals and cyanides may be present at large domestic WWTFs that accept
discharges from industrial contributors. It is the standard approach of the Division to determine the
available assimilative capacitics for cyanide and those metals for which ambient water quality standards
are available. Using the mass -balance equation provided in the beginning of Section VI, the low flows
and background concentrations contained in Section IV, and the in -stream standards for metals and
Appendix A (wQA V 7.0)
Page 15 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
cyanide as shown in Section III, the WQBELs were calculated. The data used and the resulting
WQBELs, M2i are set forth in Table A -8a for chronic standards and in Table A -8b for acute standards.
Table A -8a
Chronic WQBELs for Metals and Cyanide
Parameter
Q1 (Cfs)
Q2 Oft)
Q3 Oft)
MI
M3
M2
As, TR (µg/1)
0
3.1
3.1
0
100
100
Cd, Dis (µg/1)
0
3.1
3.1
0
6.2
6.2
Cr+3, Dis (µg/I)
0
3.1
3.1
0
231
231
Cr+6, Dis (µg/1)
0
3.1
3.1
0
11
11
Cu, Dis (µg/1)
0
3.1
3.1
0
29
29
Fe, TR (µg/1)
0
3.1
3.1
0
1000
1000
Pb, Dis (µg/1)
0
3.1
3.1
0
11
11
Mn, Dis (µg/1)
0
3.1
3.1
0
2618
2618
Hg, Tot (µg/I)
0
3.1
3.1
0
0.01
0.01
Ni, Dis (µg/1)
0
3.1
3.1
0
168
168
Se, Dis (µg/1)
0
3.1
3.1
0
4.6
4.6
Ag, Dis (µg/1)
0
3.1
3.1
0
3.5
3.5
U, Dis (µg/1)
0
3.1
3.1
0
6915
6915
Zn, Dis (µg/I)
0
3.1
3.1
0
382
382
B, Tot (mg/1)
0
3.1
3.1
0
0.75
0.75
Sulfide (mg/1)
0
3. l
3.1
0
0.002
0.002
Table A -8b
Acute WQBELs for Metals and Cyanide
Parameter
01 (cis)
Q2 (efs)
Q3 Oft)
M1
M3
M2
Al, TR (µg/1)
0
3.1
3.1
0
750
750
19
1773
16
50
5
281
4738
1513
18
22
11070
379
Cd, Dis (µg/1)
0
3.1
3.1
0
19
Cr+3, Dis (µg/1)
0
3.1
3.1
0
1773
Cr+6, Dis (µg/I)
0
3.1
3.1
0
i 6
Cu, Dis (µg/1)
0
3. l
3.1
0
50
CN, Free (µg/l)
0
3. I
3.1
0
5
Pb, Dis (µg/I)
0
3. I
3.1
0
281
Mn, Dis (µg/1)
0
3.1
3.1
0
4738
Ni, Dis (µg/1)
0
3.1
3.1
0
1513
Se, Dis (µg/I)
0
3.1
3.1
0
18.4
Ag, Dis (µg/1)
0
3.1
3.1
0
22
U, Dis (µg/1)
0
3.1
3.1
0
11070
Zn, Dis (µg/1)
0
3.1
3.1
0
379
Appendix A (WQn V 7.0)
Page 16 of 19
Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
Ammonia: The Ammonia Toxicity Model (AMMTOX) is a software program designed to project the
downstream effects of ammonia and the ammonia assimilative capacities available to each discharger
based on upstream water quality and effluent discharges. To develop data for the AMMTOX model, an
in -stream water quality study should be conducted of the upstream receiving water conditions,
particularly the pH and corresponding temperature, over a period of at least one year.
Temperature and corresponding pH data sets reflecting upstream ambient receiving water conditions
were available for the Little Thompson River at Riverwatch Station 161 (WRC 1) located in the Little
Thompson River and Weld County Road 1 near the point of confluence of No Name Creek. Ammonia
data were not available from that station. The data, reflecting a period of record from November 1992
through August 1995, were used to establish the setpoint and average headwater conditions in the
AMMTOX model. Effluent pH and temperature data were also available from the Berthoud WWTF and
were used to establish the average facility contributions in the AMMTOX model.
The AMMTOX may be calibrated for a number of variables in addition to the data discussed above.
The values used for the other variables in the model are listed below:
• Stream velocity = 0.3Qo.4d
• Default ammonia loss rate = 6/day
• pH amplitude was assumed to be medium
• Default times for pH maximum, temperature maximum, and time of day of occurrence
• pH rebound was set at the default value of 0.2 su per mile
• Temperature rebound was set at the default value of 0.7 degrees C per mile.
The results of the ammonia analyses for the Town of Berthoud WWTF are presented in Table A -9a.
Table A -10a
AMMTOX Results for the Little Thompson River
at the Town of Berthoud WWTF
Design of 2 MGD (3.1 cfs)
CHRONIC TOTAL AMMONIA, mg/L
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
5.5 6.0 5.4 4.9 4.7 3.7 2.8 3.3 3.7 3.7 4.8 5.7
ACUTE TOTAL AMMONIA, mg/L
JAN FEB MAR APR MAY, JUN JUL AUG SEP OCT NOV DEC
28.0 32.0 31.0 28.0 33.0 28.0 22.0 30.0 33.0 26.0 30.0 32.0
VII. Antidegradation Evaluation
As set out in The Basic Standards and Methodologies for Surface Water, Section 3].8(2)(6), an
antidegradation analysis is required except in cases where the receiving water is designated as "Use
Appendix A (WQA V 7.0)
Page 17 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
Protected." Note that "Use Protected" waters arc waters "that the Commission has determined do not
warrant the special protection provided by the outstanding waters designation or the antidegradation
review process" as set out in Section 31.8(2)(b). The antidegradation section of the regulation became
effective in December 2000, and therefore antidegradation considerations are applicable to this WQA
analysis.
According to the Classifications and Numeric Standards for South Platte River Basin, Laramie River
Basin, Republican River Basin, Smoky Hill River Basin, stream segment COSPBT09 is Use Protected.
Because the receiving waters arc designated as Use Protected, no antidegradation review is necessary in
accordance with the regulations. Thus, for purposes of this WQA analysis, antidegradation review
requirements have been met and no further antidegradation evaluation is necessary. Thus, an
antidegradation review is required for this segment if new or increased impacts are found to occur.
VIII. References
Regulations:
The Basic Standards and Methodologies for Surface Water, Regulation 31, Colorado Department Public
Health and Environment, Water Quality Control Commission, effective May 31, 2008.
Classifications and Numeric Standards for South Platte River Basin, Laramie River Basin, Republican
River Basin, Smoky Hill River Basin, Regulation No. 38, Colorado Department Public Health and
Environment, Water Quality Control Commission, effective 3/30/2009
Water -Quality -Limited Segments Requiring Total Maximum Daily Loads, Regulation 93, Colorado
Department Public Health and Environment, Water Quality Control Commission, effective April 30,
2008.
Colorado's Monitoring and Evaluation List, Regulation 94, Colorado Department Public Health and
Environment, Water Quality Control Commission, effective April 30, 2008.
Policy and Guidance Documents:
Antidegradation Significance Determination, for New or Increased Water Quality Impacts, Procedural
Guidance, Colorado Department Public Health and Environment, Water Quality Control Division,
December 2001.
Memorandum Re: First Update to (Antidegradation) Guidance Version 1.0, Colorado Department
Public Health and Environment, Water Quality Control Division, April 23, 2002.
Policy Concerning Escherichia coli versus Fecal Coliform, CDPHE, WQCD, July 20, 2005.
Colorado Mixing Zone Implementation Guidance, Colorado Department Public Health and
Environment, Water Quality Control Division, effective April 2002.
Policy for Conducting Assessments for Implementation of Temperature Standards in Discharge Permits,
Colorado Department Public Health and Environment, Water Quality Control Division Policy Number
Appendix A (WQA V 7.0)
Page 18 of 19 Last Revised 5/7/2009/KD
Town of Berthoud WWTF Water Quality Assessment CO -0046663
WQP-23, effective July 3, 2008.
Implementing Narrative Standards in Discharge Permits, for the Protection ofIrrigated Crops, Colorado
Department Public Health and Environment, Water Quality Control Division Policy Number WQP-24,
effective March 10, 2008.
Policy for Characterizing Ambient Water Quality for Use in Determining Water Quality Standards
Based Effluent Limits, Colorado Department Public Health and Environment, Water Quality Control
Division Policy Number WQP-19, effective May 2002.
Appendix A (WQA V 7.0)
Page 19 of 19 Last Revised 5/7/2009/KD
Permit, Part I
Page 2 of 29
Permit No. CO -0046663
TABLE OF CONTENTS
PARTI 3
A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS 3
I. Effluent Limitations, Monitoring Frequencies and Sample Types 3
2. Monitoring Frequency and Sample Type Influent Parameters 4
B. TERMS AND CONDITIONS 5
I. Service Area 5
2. Design Capacity 5
3. Expansion Requirements 5
4. Facilities Operation and Maintenance 5
5. Percentage Removal Requirements (BOD5 and TSS Limitations) 6
6. Chronic WET Testing-Outfall(s):001A 6
7. Compliance Schedule(s) 8
8. Industrial Waste Management 8
C. DEFINITION OF TERMS 10
D. General Monitoring, SAmpling and reporting requirements 13
I. Routine Reporting of Data 13
2. Annual Biosolids Report 13
3. Representative Sampling 14
4. Influent and Effluent Sampling Points 14
5. Analytical and Sampling Methods for Monitoring 14
6. Records IS
7. Flow Measuring Devices 16
8. Signatory Requirements 16
PART II 17
A. NOTIFICATION REQUIREMENTS 17
1. Notification to Parties 17
2. Change in Discharge 17
3. Special Notifications - Definitions 17
4. Noncompliance Notification I8
5. Other Notification Requirements 18
6. Bypass Notification 19
7. Upsets 19
8. Discharge Point 19
9. Proper Operation and Maintenance 20
10. Minimization of Adverse Impact 20
11. Removed Substances 20
12. Submission of Incorrect or Incomplete Information 20
13. Bypass 20
14. Reduction, Loss, or Failure of Treatment Facility 20
B. RESPONSIBILITIES 21
1. Inspections and Right to Entry 21
2. Duty to Provide Information 21
3. Transfer of Ownership or Control 21
4. Availability of Reports 22
5. Modification, Suspension, Revocation, or Termination of Permits By the Division 22
6. Oil and Hazardous Substance Liability 24
7. State Laws 24
8. Permit Violations 24
9. Property Rights 24
10. Severability 25
I I. Renewal Application 25
12. Confidentiality 25
13. Fees 25
14. Duration of Permit 25
15. Section 307 Toxics 25
16. Effect of Permit Issuance 25
PART III 27
Permit, Part I
Page 3 of 29
Permit No. CO -0046663
PART I
A. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS
1. Effluent Limitations Monitoring Frequencies and Sample Types
During the period beginning no later than the effective date of the permit and lasting through the expiration date, the
permittee is authorized to discharge from the following outfall(s). Self -monitoring samples taken in compliance with the
monitoring requirements, should be taken from the following location(s): Outfall 001A, following disinfection and to
entering the Little Thompson River.
In order to obtain an indication of the compliance or non-compliance with the effluent limitations specified in Part I, Section
A.5, the pennittee shall monitor effluent parameters at the following required frequencies, the results to be reported on the
Discharge Monitoring Report (See Part I, Section D.2.):
If the permittee, using an approved analytical method, monitors any parameter more frequently than required by this permit,
then the results of such monitoring shall be included in the calculation and reporting of the values required in the Discharge
Monitoring Report Form (DMRs) or other forms as required by the Division. Such increased frequency shall also be
indicated.
Oil and Grease Monitoring: For every outfall with oil and grease monitoring, in the event an oil sheen or floating oil is
observed, a grab sample shall be collected and analyzed for oil and grease, and reported on the appropriate DMR under
parameter 03582. In addition, corrective action shall be taken immediately to mitigate the discharge of oil and grease. A
description of the corrective action taken should be included with the DMR.
Total Residual Chlorine: Monitoring for TRC is required only when chlorine is used for disinfection.
Metals: Metals concentrations measured in compliance with the effluent monitoring requirements listed in Part I.A of this
permit may be used to satisfy any pretreatment or industrial waste management metals monitoring requirements listed in Part
1.6.8, with the potentially dissolved, dissolved, or total recoverable concentrations, as specified in Part I.A, being substituted
for the total metals concentrations specified in Part 1.B.8. However, the special sampling procedures (e.g. 24 -hour composite
samples) specified in Part 1.8.8 must be followed.
In accordance with the Water Quality Control Commission Regulations for Effluent Limitations, Section 62.4, and the
Colorado Discharge Permit System Regulations, Section 61.8(2), 5 C.C.R. 1002-61, the permitted discharge shall not contain
effluent parameter concentrations which exceed the following limitations specified below or exceed the specified flow
limitation.
2. Frequency and Sample Type Influent Parameters
Regardless of whether or not an effluent discharge occurs and in order to obtain an indication of the current influent loading
as compared to the approved capacity specified in Part I, Section A.2.; the pennittee shall monitor influent parameters at the
following required frequencies, the results to be reported on the Discharge Monitoring Report (See Part I, Section D.2.):
If the permittee monitors at the point of discharge any pollutant limited by the permit more frequently than required by the
permit, using an approved test procedure or as specified in the permit, the result of this monitoring shall be included in the
calculation and reporting of data to the Division.
Self -monitoring samples taken in compliance with the monitoring requirements specified above shall be taken at the
following location(s): 3001.
Outfall 001
Permit, Part I
Page 4 of 29
Permit No. CO -0046663
Effluent Parameter
Effluent Limitations Maximum Concentrations
Monitoring Requirements
30 -Day
'0 ay
Daily
2 -Year
Frequency *
Sample Tyne *
Average *
Average *
Maximum *
Average
Effluent Flow (MGD)
pH (su)
2 Report
6.5-9
Daily Recorder
Daily Grab
E. coli (#1100 m1) *
TRC (mg/1)
N113, Tot (mg/I) Jan
NH3, Tot (mg/I) Feb
NH3, Tot (mg/I) Mar
NH3, Tot (mg/I) Apr
NH3, Tot (mg/I) May
NH3, Tot (mg/I) Jun
NH3, Tot (mg/I) Jul
NH3, Tot (mg/I) Aug
NH3, Tot (mg/I) Sep
NH3, Tot (mg/I) Oct
NH3, Tot (mg/I) Nov
NH3, Tot (mg/I) Dec
GODS, effluent (mg/I)
BODS (% removal)
TSS, effluent (mg/I)
TSS (% renrival)
Oil and Grease (mg/I)
Cr+6, PD (µg/I)
Cu, PD (µg/l)
CN, WAD pg/1
Until 08/31/2012
Beginning 09/01/2012
Fig, Tot (µg/I)
Until 08/31/2012
Beginning 09/01/2012
Se, PD (µg/I)
126 252
0.011 0.019
5.5 28
6 32
5.4 31
4.9 28
4.7 33
3.7 38
2.8 22
3.3 30
3.7 33
3.7 26
4.8 30
5.7 32
30 45
85 (min)
30 45
85 (min)
10
Report Report
Report Report
Report
5
Report
0.01
Report Report
2 Days/Week Grab
Weekly Grab
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Calculated
Monthly Composite
Monthly Calculated
Daily Visual
Monthly Composite
Quarterly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Monthly Composite
Quarterly Composite
WET, chronic
Pirmphales Lethality
Cctiodaphnia Lethality
Pimephales Toxicity
Ceriodaphnia Toxicity
Annualyy 3 Composites / Test
Annaully 3 Composites / Test
Annaully 3 Composites / Test
Annaully 3 Composites / Test
Stat Diff&
IC25 > IWC
Report Stat
Diff&1C25
3. Monitoring Outfall 3001
Permit, Part I
Page 5 of 29
Permit No. CO -0046663
Influent Parameter
Frequency
Sample Type f/
Flow, MGD
Continuous
Recorder
BOD5, mg/1
Monthly
Composite
BOD5, lbs/day
Monthly
Composite
Total Suspended Solids, TSS, mg/I
Monthly
Composite
B. TERMS AND CONDITIONS
I. Service Area
The service area for this treatment facility is delineated in Figure I. All wastewater flows contributed in this service area may
be accepted by the Town of Berthoud for treatment at the permittee's wastewater treatment plant provided that such
acceptance does not cause or contribute to an exceedance of the throughput or design capacity of the treatment works or the
effluent limitations in Part I.A.5, or constitute a substantial impact to the functioning of the treatment works, degrade the
quality of the receiving waters, or harm human health, or the environment.
In addition, the permittee shall enter into and maintain service agreements with any municipalities that discharge into the
wastewater treatment facility. The service agreements shall contain all provisions necessary to protect the financial, physical,
and operational integrity of the wastewater treatment works.
2. Design Capacity
Based on Site Approval #4694, the design capacity of this domestic wastewater treatment works is 2 million gallons per day
(MGD) for hydraulic flow (30 -day average) and 3900 lbs. BOD5 per day for organic loading (30 -day average).
3. Expansion Requirements
Pursuant to Colorado Law, C.R.S. 25-8-501 (5 d & e), the permittee is required to initiate engineering and financial planning
for expansion of the domestic wastewater treatment works whenever throughput reaches eighty (80) percent of the treatment
capacity. Such planning may be deemed unnecessary upon a showing that the area served by the domestic wastewater
treatment works has a stable or declining population; but this provision shall not be construed as preventing periodic review
by the Division should it be felt that growth is occurring or will occur in the area.
The permittee shall commence construction of such domestic wastewater treatment works expansion whenever throughput
reaches ninety-five (95) percent of the treatment capacity or, in the case of a municipality, either commence construction or
cease issuance of building permits within such municipality until such construction is commenced; except that building
permits may continue to be issued for any construction which would not have the effect of increasing the input of wastewater
to the sewage treatment works of the municipality involved.
Where unusual circumstances result in throughput exceeding 80% of treatment capacity, the permittee may, in lieu of
initiating planning for expansion, submit a report to the Division that demonstrates that it is unlikely that the event will
reoccur, or even if it were to reoccur, that 95% of the treatment capacity would not be exceeded.
Where unusual circumstances result in throughput exceeding 95% of the treatment capacity, the permittee may, in lieu of
initiating construction of the expansion, submit a report to the Division that demonstrates that the domestic wastewater
treatment works was in compliance at all times during the events and that it is extremely unlikely that the event will reoccur.
Where the pennittee submits a report pursuant to unusual circumstances, and the Division, upon review of such report,
determines in writing to the permittee that the. report does not support the required findings, the permittee shall initiate
planning and/or construction of the domestic wastewater treatment works as appropriate.
4. Facilities Operation and Maintenance
The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control including all
portions of the collection system and lift stations owned by the permittee (and related appurtenances) which are installed or
Permit, Part I
Page 6 of 29
Permit No. CO -0046663
used by the permittee as necessary to achieve compliance with the conditions of this permit. Proper operation and
maintenance also includes adequate laboratory controls and appropriate quality assurance procedures. This provision requires
the operation of back-up or auxiliary facilities or similar systems when installed by the permittee only when necessary to
achieve compliance with the conditions of the permit. However, the permittee shall operate, at a minimum, one complete set
of each main line unit treatment process whether or not this process is needed to achieve permit effluent compliance. Any
sludge produced at the wastewater treatment facility shall be disposed of in accordance with State and Federal guidelines and
regulations.
5. Percentage Removal Requirements (BOD5 and TSS Limitations)
If noted in the above limits table(s), the arithmetic mean of the BOD5 and TSS concentrations for effluent samples collected
during the calendar month shall demonstrate a minimum of eighty-five percent (85%) removal of both BOD5 and TSS, as
measured by dividing the respective difference between the mean influent and effluent concentrations for the calendar month
by the respective mean influent concentration for the calendar month, and multiplying the quotient by 100.
6. Chronic WET Testing-Outfall(s):001A
a. Chronic WET Testing and Reporting Requirements
Tests shall be done at the frequency listed in Part I.A.I. Test results shall be reported along with the Discharge
Monitoring Report (DMR) submitted for the reporting period during which the sample was taken. (i.e., WET testing
results for the first calendar quarter ending March 31 shall be reported with the DMR due April 28.) The results shall be
submitted on the Chronic Toxicity Test report form, available from the Division. Copies of these reports are to be
submitted to the Division along with the DMR.
The permittee shall conduct each chronic WET test in general accordance with methods described in Short Term
Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms, Fourth
Edition, October 2002, EPA 821-R-02-013 or the most current edition. The permittee shall conduct such tests using
Ceriodaphnia dubia and fathead minnows.
b. Failure of Test and Division Notification
A chronic WET test is failed whenever 1) there is a statistically significant difference in lethality between the control and
any effluent concentration less than the instream waste concentration ("IWC") and, 2) the IC,5, which represents an
estimate of the effluent concentration at which 25% of the test organisms demonstrate inhibition as reflected by lethality,
is at any effluent concentration less than the IWC. The 1WC for this permit has been determined to be 100%. The
permittee must provide written notification of the failure of a WET test to the Division, along with a statement as to
whether a Preliminary Toxicity Investigation ("PTI")/Toxicity Identification Evaluation ("TIE") or accelerated testing is
being performed. Notification must be received by the Division within 21 calendar days of the demonstration of
chronic WET in the routine required test. "Demonstration" for the purposes of Part I.B.6.b, c, d and I means no later
than the last day of the laboratory test.
c. Automatic Compliance Schedule Upon Failure of Test
If a routine chronic WET test is failed, regardless of whether the limit is in effect, the following automatic compliance
schedule shall apply. As part of this, the permittee shall either:
i. Proceed to conduct the PTI/TIE investigation as described in Part 1.B.6.d., or
ii. Conduct accelerated testing using the single species found to be more sensitive.
If accelerated testing is being performed, the permittee shall provide written notification of the results within 14
calendar days of completion of the "Pattern of Toxicity"/"No Toxicity" demonstration. Testing will be at least
once every two weeks for up to five tests until; 1) two consecutive tests fail or three of five tests fail, in which case a
pattern of toxicity has been demonstrated or 2) two consecutive tests pass or three of five tests pass, in which case no
pattern of toxicity has been found. If no pattern of toxicity is found the toxicity episode is considered to be ended and
routine testing is to resume. If a pattern of toxicity is found, a PTI/TIE investigation is to be performed. If a pattern of
Permit, Part I
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Permit No. CO -0046663
toxicity is not demonstrated but a significant level of erratic toxicity is found, the Division may require an increased
frequency of routine monitoring or some other modified approach.
d. PTI/TIE
The results of the PTI/TIE investigation are to be received by the Division within 120 days of the demonstration
of chronic WET in the routine test, as defined above, or if accelerated testing is performed, the date the pattern of
toxicity is demonstrated. A status report is to be provided to the Division at the 30, 60 and 90 day points of the
PTI/TIE investigation. The Division may extend the time frame for investigation where reasonable justification exists.
A request for an extension must be made in writing and received prior to the 120 day deadline. Such request must
include a justification and supporting data for such an extension.
The permittee may use the time for investigation to conduct a PTI or move directly into the TIE. A PTI consists of a
brief search for possible sources of WET, which might reveal causes of such toxicity and appropriate corrective actions
more simply and cost effectively than a formal TIE. If the PTI allows resolution of the WET incident, the TIE need not
necessarily be conducted. I f, however, WET is not identified or resolved during the PTI, the TIE must be conducted
within the allowed 120 day time frame.
Any permittee that is required to conduct a PTI/TIE investigation shall do so in conformance with procedures identified
in the following documents, or as subsequently updated: 1) Toxicity Identification Evaluation: Characterization of
Chronically Toxic Effluents, Phase I, EPA/600/6-91/005F May 92, 2) Methods for Aquatic Toxicity Identification
Evaluations, Phase I Toxicity Characterization Procedures, EPA/600/6-91/003 Feb. 91 and 3) Methods for Aquatic
Toxicity Identification Evaluations, Phase 11 Toxicity Identification Procedures, EPA/600/3-88/035 Feb. 1989.
A fourth document in this series is Methods for Aquatic Toxicity Identification Evaluations, Phase III Toxicity
Confirmation Procedures EPA/600/3-88/036 Feb. 1989. As indicated by the title, this procedure is intended to confirm
that the suspected toxicant is truly the toxicant. This investigation is optional.
Within 90 days of the determination of the toxicant or no later than 210 days after demonstration of toxicity, whichever is
sooner, a control program is to be developed and received by the Division. The program shall set down a method and
procedure for elimination of the toxicity to acceptable levels.
e. Request For Relief
The permittee may request relief from further investigation and testing where the toxicant has not been determined and
suitable treatment does not appear possible. In requesting such relief, the pennittee shall submit material sufficient to
establish the following:
i. It has complied with tens and conditions of the permit compliance schedule for the PTI/TIE investigation and other
appropriate conditions as may have been required by the WQCD;
ii. During the period of the toxicity incident it has been in compliance with all other permit conditions, including, in the
case of a POTW, pretreatment requirements;
iii. During the period of the toxicity incident it has properly maintained and operated all facilities and systems of
treatment and control; and
iv. Despite the circumstances described in paragraphs (i) and (iii) above, the source and/or cause of toxicity could not be
located or resolved.
If deemed appropriate by the Division, the permit or the compliance schedule may be modified to revise the ongoing
monitoring and toxicity investigation requirements to avoid an unproductive expenditure of the permittee's resources,
provided that the underlying obligation to eliminate any continuing exceedance of the toxicity limit shall remain.
f Spontaneous Disappearance
If toxicity spontaneously disappears at any time after a test failure, the pennittee shall notify the Division in writing
within 14 days of a demonstration of disappearance of the toxicity. The Division may require the permittee to develop
and submit additional information, which may include, but is not limited to, the results of additional testing. If no pattern
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Permit No. CO -0046663
of toxicity is identified or recurring toxicity is not identified, the toxicity incident response is considered closed and
normal WET testing shall resume.
g.
Toxicity Reopener
This permit may be reopened and modified (following proper administrative procedures) to include new compliance
dates, additional or modified numerical permit limitations, a new or different compliance schedule, a change in the whole
effluent toxicity testing protocol, or any other conditions related to the control of toxicants if one or more of the
following events occur:
i. Toxicity has been demonstrated in the effluent and the permit does not contain a toxicity limitation.
ii. The PTI/TIE results indicate that the identified toxicant(s) represent pollutant(s) that may be controlled with specific
numerical limits and the permit issuing authority agrees that the control of such toxicants through numerical limits is
the most appropriate course of action.
iii. The PTI/TIE reveals other unique conditions or characteristics, which, in the opinion of the permit issuing authority,
justify the incorporation of unanticipated special conditions in the permit.
7. Compliance Schedule(s)
a. Activities to Meet Cyanide and Total Mercury Final Limits — In order to meet the cyanide and total mercury limitations,
the following schedule will be included in the perniit. If the pennittee determines that upgrades to the facility will need
to be made to meet these limitations, note that this will be subject to a site approval amendment and Division review of
facility plans.
Code Event
Description
Permit Citation Due Date
43699 Facility
Evaluation Plan
00899 Implementation
Schedule
CSOl7 Achieve Final
Compliance
with Emissions
or Discharge
Limits
Submit a report that identifies sources of cyanide and mercury to Part I.A.7. 08/31/10
the wastewater treatment facility and identifies strategies to
control these sources or treatment alternatives such that
compliance with the final limitations may be attained.
Submit a progress report summarizing the progress in Part I.A.7. 08/31/11
implementing the strategies to control sources such that
compliance with the final cyanide and mercury limitations may be
attained.
Submit study results that show compliance has been attained with Part 1.A.7. 08/31/12
the final cyanide and mercury limitations.
All information and written reports required by the following compliance schedules should be directed to the Permits Unit for
final review unless otherwise stated.
8. Industrial Waste Management
a. The Permittee has the responsibility to protect the Domestic Wastewater Treatment Works (DWTW), as defined at
section 25.8.103(5) of the Colorado Water Quality Control Act, or the Publicly -Owned Treatment Works (POTW), as
defined at 40 CFR section 403.3(q) of the federal pretreatment regulations, from pollutants which would cause pass
through or interference, as defined at 40 CFR 403.3(p) and (k), or otherwise be incompatible with operation of the
treatment works including interference with the use or disposal of municipal sludge.
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Permit No. CO -0046663
b. Pretreatment Standards (40 CFR Section 403.5) developed pursuant to Section 307 of the Federal Clean Water Act (the
Act) require that the Permittee shall not allow, under any circumstances, the introduction of the following pollutants to
the DWTW from any source of non -domestic discharge:
i. Pollutants which create a fire or explosion hazard in the DWTW, including, but not limited to, wastestreams with a
closed cup flashpoint of less than sixty (60) degrees Centigrade (140 degrees Fahrenheit) using the test methods
specified in 40 CFR Section 261.21;
ii. Pollutants which will cause corrosive structural damage to the DWTW, but in no case discharges with a pH of lower
than 5.0 s.u., unless the treatment facilities are specifically designed to accommodate such discharges;
iii. Solid or viscous pollutants in amounts which will cause obstruction to the flow in the DWTW, or otherwise interfere
with the operation of the DWTW;
iv. Any pollutant, including oxygen demanding pollutants (e.g., BOD), released in a discharge at a flow rate and/or
pollutant concentration which will cause Interference with any treatment process at the DWTW;
v. Heat in amounts which will inhibit biological activity in the DWTW resulting in Interference, but in no case heat in
such quantities that the temperature at the DWTW treatment plant exceeds forty (40) degrees Centigrade (104
degrees Fahrenheit) unless the Approval Authority, upon request of the DWTW, approves alternate temperature
limits;
vi. Petroleum oil, non -biodegradable cutting oil, or products of mineral oil origin in amounts that will cause Interference
or Pass Through;
vii. Pollutants which result in the presence of toxic gases, vapors, or fumes within the DWTW in a quantity that may
cause acute worker health and safety problems;
viii. Any trucked or hauled pollutants, except at discharge points designated by the DWTW; and
ix. Any specific pollutant that exceeds a local limitation established by the Permittee in accordance with the
requirements of 40 CFR Section 403.5(c) and (d).
x. Any other pollutant which may cause Pass Through or Interference.
c. EPA shall be the Approval Authority and the mailing address for all reporting and notifications to the Approval
Authority shall be: USEPA 1595 Wynkoop St. 8ENF-W-NP, Denver, CO 80202-1129. Should the State be delegated
authority to implement and enforce the Pretreatment Program in the future, the Permittee shall be notified of the
delegation and the state permitting authority shall become the Approval Authority.
d. In addition to the general limitations expressed above, more specific Pretreatment Standards have been and will be
promulgated for specific industrial categories under Section 307 of the Act (40 CFR Part 405 et. seq.).
e. The Permittee must notify the state permitting authority and the Approval Authority, of any new introductions by new or
existing industrial users or any substantial change in pollutants from any industrial user within sixty (60) days following
the introduction or change. Such notice must identify:
i. Any new introduction of pollutants into the DWTW from an industrial user which would be subject to Sections 301,
306, or 307 of the Act if it were directly discharging those pollutants; or
ii. Any substantial change in the volume or character of pollutants being introduced into the DWTW by any industrial
user;
iii. For the purposes of this section, adequate notice shall include information on:
(A) The identity of the industrial user;
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Permit No. CO -0046663
(B) The nature and concentration of pollutants in the discharge and the average and maximum flow of the
discharge to be introduced into the DWTW; and
(C) Any anticipated impact of the change on the quantity or quality of effluent to be discharged from or
biosolids or sludge produced at such DWTW.
iv. For the purposes of this section, an industrial user shall include:
(A) Any discharger subject to Categorical Pretreatment Standards under Section 307 of the Act and 40
CFR chapter I and subchapter N;
(B) Any discharger which has a process wastewater flow of 25,000 gallons or more per day;
(C) Any discharger contributing five percent or more of the average dry weather hydraulic or organic
capacity of the DWTW treatment plant;
(D) Any discharger who is designated by the Approval Authority as having a reasonable potential for
adversely affecting the DWTWs operation or for violating any Pretreatment Standard or requirements;
f. At such time as a specific Pretreatment Standard or requirement becomes applicable to an industrial user of the Permittee,
the state permitting authority and/or Approval Authority may, as appropriate:
Amend the Permittee's CDPS discharge permit to specify the additional pollutant(s) and corresponding effluent
limitation(s) consistent with the applicable national Pretreatment Standards;
ii. Require the Permittee to specify, by ordinance, order, or other enforceable means, the type of pollutant(s) and the
maximum amount which may be discharged to the Pennittee's DWTW for treatment. Such requirement shall be
imposed in a manner consistent with the program development requirements of the General Pretreatment Regulations
at 40 CFR Part 403; and/or,
iii. Require the Permittee to monitor its discharge for any pollutant which may likely be discharged from the Permittee's
DWTW, should the industrial user fail to properly pretreat its waste.
The state permitting authority and the Approval Authority retains, at all times, the right to take legal action against any source
of nondomestic discharge, whether directly or indirectly controlled by the Permittee, for violations of a permit, order or
similar enforceable mechanism issued by the Permittee, violations of any Pretreatment Standard or requirement, or for failure
to discharge at an acceptable level under national standards issued by EPA under 40 CFR, chapter I, subchapter N. In those
cases where a CDPS permit violation has occurred because of the failure of the Permittee to properly develop and enforce
Pretreatment Standards and requirements as necessary to protect the DWTW, the state permitting authority and/or Approval
Authority shall hold the Permittee and/or industrial user responsible and may take legal action against the Permittee as well as
the Industrial user(s) contributing to the permit violation.
C. DEFINITION OF TERMS
I_ "Acute Toxicity" means there shall be no acute toxicity in the effluent from this discharge point. The acute toxicity limitation
is exceeded if 1) a statistically significant difference in mortality (at the 95% confidence level) is observed for either species
between the control and any dilution less than or equal to the identified IWC or 2) a species mortality in any dilution of
effluent (including 100% effluent) exceeds 50%.
2. "Chronic lethality" occurs when a statistically significant difference, at the 95% confidence level, occurs in the chronic test
between the mortality of the test species in 100% effluent (the chronic IWC = 100%) and the control.
3. "Composite" sample is a minimum of four (4) grab samples collected at equally spaced two (2) hour intervals and
proportioned according to flow.
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Permit No. CO -0046663
4. "Continuous" measurement, is a measurement obtained from an automatic recording device which continually measures
provides measurements.
5. "Daily Maximum limitation" for all parameters except temperature, means the limitation for this parameter shall be applied as
an instantaneous maximum (or, for pH or DO, instantaneous minimum) value. The instantaneous value is defined as the
analytical result of any individual sample. DMRs shall include the maximum (and/or minimum) of all instantaneous values
within the calendar month. Any instantaneous value beyond the noted daily maximum limitation for the indicated parameter
shall be considered a violation of this permit.
6. "Daily Maximum Temperature (DM)" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as
the highest two-hour average water temperature recorded during a given 24 -hour period.
7. "Dissolved (D) metals fraction" is defined in the Basic Standards and Methodologies for Surface Water 1002-31, as that
portion of a water and suspended sediment sample which passed through a 0.40 or 0.45 UM (micron) membrane filter.
Determinations of "dissolved" constituents are made using the filtrate. This may include some very small (colloidal)
suspended particles which passed through the membrane filter as well as the amount of substance present in true chemical
solution.
8. "Geometric mean" for fecal coliform and E. coli bacteria concentrations, the thirty (30) day and seven (7) day averages shall
be determined as the geometric mean of all samples collected in a thirty (30) day period and the geometric mean of all
samples taken in a seven (7) consecutive day period respectively. The geometric mean may be calculated using two different
methods. For the methods shown, a, b, c, d, etc. are individual sample results, and n is the total number of samples.
Method 1:
om>
Geometric Mean = (a*b*c*d*...) "*" - means multiply
Method 2:
Geometric Mean = antilog ( [log(a)+Iog(b)+log(c)+log(d)+.._]/n )
Graphical methods, even though they may also employ the use of logarithms, may introduce significant error and may not be
used.
In calculating the geometric mean, for those individual sample results that are reported by the analytical laboratory to be "less
than" a numeric value, a value of I should be used in the calculations. If all individual analytical results for the month are
reported to be less than numeric values, then report "less than" the largest of those numeric values on the monthly DMR.
Otherwise, report the calculated value.
For any individual analytical result of "too numerous to count" (TNTC), that analysis shall be considered to be invalid and
another sample shall be promptly collected for analysis. If another sample cannot be collected within the same sampling
period for which the invalid sample was collected (during the same month if monthly sampling is required, during the same
week if weekly sampling is required, etc.), then the following procedures apply:
i. A minimum of two samples shall be collected for coliform analysis within the next sampling period.
ii. If the sampling frequency is monthly or less frequent: For the period with the invalid sample results, leave the
spaces on the corresponding DMR for reporting coliform results empty and attach to the DMR a letter noting that a
result of TNTC was obtained for that period, and explain why another sample for that period had not been collected.
If the sampling frequency is more frequent than monthly: Eliminate the result of TNTC from any further calculations, and
use all the other results obtained within that month for reporting purposes. Attach a letter noting that a result of TNTC was
obtained, and list all individual analytical results and corresponding sampling dates for that month.
9. "Grab" sample, is a single "dip and take" sample so as to be representative of the parameter being monitored.
10. "In -situ" measurement is defined as a single reading, observation or measurement taken in the field at the point of discharge.
Permit, Part
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Permit No. CO -0046663
11. "Instantaneous" measurement is a single reading, observation, or measurement performed on site using existing monitoring
facilities.
12. "Maximum Weekly Average Temperature (MWAT)" is defined in the Basic Standards and Methodologies for Surface Water
1002-31, as an implementation statistic that is calculated from field monitoring data. The MWAT is calculated as the largest
mathematical mean of multiple, equally spaced, daily temperatures over a seven-day consecutive period, with a minimum of
three data points spaced equally through the day. For lakes and reservoirs, the MWAT is assumed to be equivalent to the
maximum WAT from at least three profiles distributed throughout the growing season (generally July -September).
13. "Potentially dissolved (PD) metals fraction" is defined in the Basic Standards and Methodologies for Surface Water 1002-31,
as that portion of a constituent measured from the filtrate of a water and suspended sediment sample that was first treated with
nitric acid to a pH of 2 or less and let stand for 8 to 96 hours prior to sample filtration using a 0.40 or 0.45 -UM (micron)
membrane filter. Note the "potentially dissolved" method cannot be used where nitric acid will interfere with the analytical
procedure used for the constituent measured.
14. "Quarterly measurement frequency" means samples may be collected at any time during the calendar quarter if a continual
discharge occurs. If the discharge is intermittent, then samples shall be collected during the period that discharge occurs.
15. "Recorder" requires the continuous operation of a chart and/or totalizer (or drinking water rotor meters or pump hour meters
where previously approved.)
16. "Seven (7) day average" means, with the exception of fecal coliform or E. coli bacteria (see geometric mean), the arithmetic
mean of all samples collected in a seven (7) consecutive day period. When calculating the 7 -day average, a value of zero
should be used in place of any value that is less than the reporting limit. If all values are less than the PQL, and the PQL
is greater than the permit limit "BDL" should be reported. If all values are less than the PQL, and the PQL is less
than or equal to the permit limit, "<x" should be reported, where "x" is the reporting limit. Otherwise, the calculated
average shall be reported. Note that it does not matter if a calculated average is greater or less than the PQL, it must
be reported as a value. Such seven (7) day averages shall be calculated for all calendar weeks, which are defined as
beginning on Sunday and ending on Saturday. If the calendar week overlaps two months (i.e. the Sunday is in one month and
the Saturday in the following month), the seven (7) day average calculated for that calendar week shall be associated with the
month that contains the Saturday. Samples may not be used for more than one (1) reporting period.
17. "Thirty (30) day average" means, except for fecal coliform or E. coli bacteria (see geometric mean), the arithmetic mean of all
samples collected during a thirty (30) consecutive -day period. When calculating the 30 -day average, a value of zero should
be used in place of any value that is less than the PQL. If all values are less than the PQL, and the PQL is greater than
the permit limit "BDL" should be reported. If all values are less than the PQL, and the PQL is less than or equal to
the permit limit, "<x" should be reported, where "x" is the reporting limit. Otherwise, the calculated average shall be
reported. Note that it does not matter if a calculated average is greater or less than the PQL, it must be reported as a
value. The permittee shall report the appropriate mean of all self -monitoring sample data collected during the calendar month
on the Discharge Monitoring Reports. Samples shall not be used for more than one (I) reporting period.
18. "Total Inorganic Nitrogen (T.I.N.)" is an aggregate parameter determined based on ammonia, nitrate and nitrite
concentrations. Given that there arc no approved analytical procedures for determining T.I.N. itself as an aggregate
parameter, daily maximum and 30 -day average concentrations for T.I.N. shall be determined using the calculated T.I.N.
concentrations versus T.I.N. analytical results. Specifically, the facility must monitor for total ammonia and total nitrate plus
nitrite on the same days. The calculated T.I.N. concentrations in mg/L shall then be determined as the sum of the analytical
results of same -day sampling for total ammonia (as N) in mg/L, and total nitrate plus nitrite (as N) in mg/L. From these
calculated T.I.N. concentrations in mg/L, the daily maximum and 30 -day average concentrations must then be determined in
the same manner as the previously set out definitions.
19. "Total Metals" means the concentration of metals determined on an unfiltered sample following vigorous digestion (Section
4.1.3), or the sum of the concentrations of metals in both the dissolved and suspended fractions, as described in Manual of
Methods for Chemical Analysis of Water and Wastes, U.S. Environmental Protection Agency, March 1979, or its equivalent.
20. "Total Recoverable Metals" means that portion of a water and suspended sediment sample measured by the total recoverable
analytical procedure described in Methods for Chemical Analysis of Water and Wastes U.S. Environmental Protection
Agency, March 1979 or its equivalent.
Permit, Part I
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Permit No. CO -0046663
21. "Twenty four (24) hour composite" sample is a combination of at least eight (8) sample aliquots of at least 100 milliliters,
collected at equally spaced intervals during the operating hours of a facility over a twenty-four (24) hour period. For volatile
pollutants, aliquots must be combined in the laboratory immediately before analysis. The composite must be flow
proportional; either the time interval between each aliquot or the volume of each aliquot must be proportional to either the
wastewater or effluent flow at the time of sampling or the total wastewater or effluent flow since the collection of the
previous aliquot. Aliquots may be collected manually or automatically.
22. "Twice Monthly" monitoring frequency means that two samples shall be collected each calendar month on separate weeks
with at least one full week between the two sample dates. Also, there shall be at least one full week between the second
sample of a month and the first sample of the following month.
23. "Visual" observation is observing the discharge to check for the presence of a visible sheen or floating oil
24. "Water Quality Control Division" or "Division" means the state Water Quality Control Division as established in 25-8-101 et
al.)
Additional relevant definitions are found in the Colorado Water Quality Control Act, CRS §§ 25-8-101 et seq., the Colorado
Discharge Permit System Regulations, Regulation 61 (5 CCR 1002-61) and other applicable regulations.
D. GENERAL MONITORING, SAMPLING AND REPORTING REQUIREMENTS
1. Routine Reporting of Data
Reporting of the data gathered in compliance with Part I.B.I shall be on a monthly basis. Reporting of all data gathered shall
comply with the requirements of Part I.E. (General Requirements). Monitoring results shall be summarized for each calendar
month and reported on Division approved discharge monitoring report (DMR) forms (EPA form 3320-I). One form shall be
mailed to the Water Quality Control Division, as indicated below, so that the DMR is received no later than the 28th day of
the following month (for example, the DMR for the first calendar quarter must be received by the Division by April 28th). If
no discharge occurs during the reporting period, "No Discharge" shall be reported.
The original signed copy of each discharge monitoring report (DMR) shall be submitted to the Division at the following
address:
Colorado Department of Public Health and Environment
Water Quality Control Division
WQCD-P-B2
4300 Cherry Creek Drive South
Denver, Colorado 80246-1 53 0
The Discharge Monitoring Report forms shall be filled out accurately and completely in accordance with requirements of this
permit and the instructions on the forms. They shall be signed by an authorized person as identified in Part I.E.6.
2. Annual Biosolids Report
The permittee shall provide the results of all biosolids monitoring and information on management practices, land application
sites, site restrictions and certifications. Such information shall be provided no later than February 19th of each year.
Reports shall be submitted addressing all such activities that occurred in the previous calendar year. If no biosolids were
applied to the land during the reporting period, "no biosolids applied" shall be reported. Until further notice, biosolids
monitoring results shall be reported on forms, or copies of forms, provided by the Division. Annual Biosolids Reports
required herein, shall be signed and certified in accordance with the Signatory Requirements, Part I.D.I, and submitted as
follows:
The original copy of each form shall be submitted to the following address:
COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT,
WATER QUALITY CONTROL DIVISION
Permit, Part I
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Permit No. CO -0046663
WQCD-PERMITS-B2
4300 CHERRY CREEK DRIVE SOUTH
DENVER, COLORADO 80246-1530
A copy of each form shall be submitted to the following address:
WATER PROGRAM REGIONAL BIOSOLIDS PROGRAM
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION VIII,
1595 WYNKOOP STREET
DENVER, CO 80202-2466
ATTENTION: BIOSOLIDS PROGRAM MANAGER
3. Representative Sampling
Samples and measurements taken for the respective identified monitoring points as required herein shall be representative of
the volume and nature of: I) all influent wastes received at the facility, including septage, biosolids, etc.; 2) the monitored
effluent discharged from the facility; and 3) biosolids produced at the facility. All samples shall be taken at the monitoring
points specified in this permit and, unless otherwise specified, before the influent, effluent, or biosolids wastestream joins or
is diluted by any other wastestream, body of water, or substance. Monitoring points shall not be changed without notification
to and prior approval by the Division.
4. Influent and Effluent Sampling Points
Influent and effluent sampling points shall be so designed or modified so that: 1) a sample of the influent can be obtained
after preliminary treatment and prior to primary or biological treatment and 2) a sample of the effluent can be obtained at a
point after the final treatment process and prior to discharge to state waters. The permittee shall provide access to the
Division to sample at these points.
5. Analytical and Sampling Methods for Monitoring
The pennittee shall install, calibrate, use and maintain monitoring methods and equipment, including biological and indicated
pollutant monitoring methods. All sampling shall be performed by the permittee according to specified methods in 40 C.F.R.
Part 136; methods approved by EPA pursuant to 40 C.F.R. Part 136; or methods approved by the Division, in the absence of a
method specified in or approved pursuant to 40 C.F.R. Part 136.
The analytical method and PQL selected for a parameter shall be the one that can measure compliance with the
permit limitation. If all analytical methods and corresponding PQLs are greater than the permit limit, then the
analytical method with the lowest PQL shall be used. if the permit contains a monitoring or report only requirement,
the analytical method with the lowest PQL shall be used.
When the analytical method which complies with the above requirements has a PQL greater than the permit limit, the
permittee shall report "BDL" on the DMR. Such reports will not be considered as violations of the permit limit, as
long as the lowest available PQL is used for the analysis. When the analytical method which complies with the above
requirements has a PQL that is equal to or less than the permit limitation, "< X" (where X = the actual PQL used)
shall be reported on the DMR. For parameters that have only a monitoring or report only limitation, "< X" (where X
= the actual PQL used) shall be reported on the DMR.
The present lowest PQLs for specific parameters, as determined by the State Laboratory (November 2008) are provided
below for reference. Note that these PQLs are not necessarily the PQLs required to be used in this permit, dependent upon
the requirements laid out in bold above. For a listing of the PQLs for organic parameters, please refer to the Division's
Practical Quantitation Limitation Guidance Document, July 2008. Future requirements for metals PQLs will be contained in
the Division's Practical Quantitation Limitation Guidance Document for Metals.
Permit, Part I
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Permit No. CO -0046663
Parameter
Practical
Quantitation
Limits,
Parameter
Practical
Quantitation
Limits, µg/I
Aluminum
50 µg/I
Manganese
2 µg/I
Ammonia
1 mg/I
Mercury
0.1 µg/1
Arsenic
1 µg/I
Mercury (low-level)
0.003 µg/1
Barium
5 µg/I
Nickel
50 µg/I
Beryllium
1µg/I
N -Ammonia
50 µg/I
BOD / CBOD
1 mg/I
N Nitrate/Nitrite
0.5 mg/I
Boron
50 µg/I
N -Nitrate
50 µg/I
Cadmium
1 µg/I
N -Nitrite
10 µg/1
Calcium
20 µg/1
Total Nitrogen
0.5 mg/I
Chloride
2 mg/1
Phenols
100 µg/I
Chlorine
0.1 mg/I
Phosphorus
10 µg/1
Total Residual Chlorine
Radium 226
1 pCi/1
DPD colorimetric
0.10 mg/1
Radium 228
I pCi/I
Amperometric titration
0.05 mg/I
Selenium
I µg/I
Chromium
20 µg/I
Silver
0.5 µg/1
Chromium, Hexavalent
20 µg/I
Sodium
0.2 mg/I
Copper
5 µg/I
Sulfate
5 mg/I
Cyanide (Direct / Distilled)
10 µg/I
Sulfide
0.2 mg/I
Cyanide, WAD+A47
5 µg/I
Total Dissolved Solids
10 mg/I
Fluoride
0.1 mg/I
Total Suspended Solids
10 mg/1
Iron
10 µg/I
Thallium
1 µg/I
Lead
1 µg/I
Uranium
1 µg/I
Magnesium
20 µg/I
Zinc
10 µg/I
These limits apply to the total recoverable or the potentially dissolved fraction of metals.
For hexavalent chromium, samples must be unacidified so dissolved concentrations will be measured rather than
potentially dissolved concentrations.
In the calculation of average concentrations, those analytical results that are less than the practical quantitation limit shall
be considered to be zero for calculation purposes. If all individual analytical results that would be used in the
calculations are below the practical quantitation limit, then "less than x ", where x is the practical quantitation limit, shall
be reported on the monthly DMR. Otherwise, report the calculated value.
6. Records
a. The permittee shall establish and maintain records. Those records shall include, but not be limited to, the following:
i. The date, type, exact place, and time of sampling or measurements;
ii. The individual(s) who performed the sampling or measurements;
Hi. The date(s) the analyses were performed;
iv. The individual(s) who performed the analyses;
v. The analytical techniques or methods used; and
vi. The results of such analyses.
b. The permittee shall retain for a minimum of three (3) years records of all monitoring information, including all original
strip chart recordings for continuous monitoring instrumentation, all calibration and maintenance records, copies of all
reports required by this permit and records of all data used to complete the application for this permit. This period of
retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the
permittee or when requested by the Division or Regional Administrator.
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7. Flow Measuring Devices
Flow metering at the headworks shall be provided to give representative values of throughput and treatment of the wastewater
system. The metering device shall be equipped with a local flow indication instrument and a flow
indication-recording-totalization device suitable for providing permanent flow records, which should be in the plant control
building. For mechanical facilities, where influent flow metering is not practical and the same results may be obtained from
metering at the effluent end of the treatment facility, this type of flow metering arrangement will be considered. For lagoons,
an instantaneous or continuous effluent flow measuring device shall be required in addition to the above described influent
flow measuring device. At the request of the Division, the permittee must be able to show proof of the accuracy of any
flow -measuring device used in obtaining data submitted in the monitoring report. The flow -measuring device must indicate
values within ten (10) percent of the actual flow entering the facility.
8. Signatory Requirements
a. All reports and other information required by the Division, shall be signed and certified for accuracy by the permittee in
accord with the following criteria:
i) In the case of corporations, by a responsible corporate officer. For purposes of this section, the responsible
corporate officer is responsible for the overall operation of the facility from which the discharge described in the
form originates;
ii) In the case of a partnership, by a general partner;
iii) In the case of a sole proprietorship, by the proprietor;
iv) In the case of a municipal, state, or other public facility, by either a principal executive officer, or ranking elected
official. For purposes of this section, a principal executive officer has responsibility for the overall operation of the
facility from which the discharge originates;
v) By a duly authorized representative of a person described above, only if:
1) The authorization is made in writing by a person described in i, ii, iii, or iv above;
2) The authorization specifies either an individual or a position having responsibility for the overall operation of
the regulated facility or activity such as the position of plant manager, operator of a well or a well field,
superintendent, position of equivalent responsibility, or an individual or position having overall responsibility
for environmental matters for the company. (A duly authorized representative may thus be either a named
individual or any individual occupying a named position); and,
3) The written authorization is submitted to the Division.
b. If an authorization as described in this section is no longer accurate because a different individual or position has
responsibility for the overall operation of the facility, a new authorization satisfying the requirements of this section must
be submitted to the Division prior to or together with any reports, information, or applications to be signed by an
authorized representative.
The permittee, or the duly authorized representative shall make and sign the following certification on all such
documents:
"I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in
accordance with a system designed to assure that qualified personnel properly gather and evaluate the information
submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible
for gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and
complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine
and imprisonment for knowing violations."
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Permit No. CO -0046663
PART II
A. NOTIFICATION REQUIREMENTS
1. Notification to Parties
All notification requirements under this section shall be directed as follows:
a. Oral Notifications, during normal business hours shall be to:
Water Quality Protection Section - Domestic Compliance Program
Water Quality Control Division
Telephone: (303) 692-3500
b. Written notification shall be to:
Water Quality Protection Section - Domestic Compliance Program
Water Quality Control Division
Colorado Department of Public Health and Environment
WQCD-WQP-B2
4300 Cherry Creek Drive South
Denver, CO 80246-1530
2. Change in Discharge
The permittee shall notify the Division, in writing, of any planned physical alterations or additions to the permitted facility.
Notice is required only when:
a. The alteration or addition could significantly change the nature or increase the quantity of pollutants discharged, or;
b. The alteration or addition results in a significant change in the permittee's sludge use or disposal practices, and such
alteration, addition, or change may justify the application of permit conditions that are different from or absent in the
existing permit, including notification of additional use or disposal sites not reported pursuant to an approved land
application plan.
The permittee shall give advance notice to the Division of any planned changes in the permitted facility or activity which may
result in noncompliance with permit requirements.
Whenever notification of any planned physical alterations or additions to the permitted facility is required pursuant to this
section, the permittee shall furnish the Division such plans and specifications which the Division deems reasonably necessary
to evaluate the effect on the discharge, the stream, or ground water. If the Division finds that such new or altered discharge
might be inconsistent with the conditions of the permit, the Division shall require a new or revised permit application and
shall follow the procedures specified in Sections 61.5 through 61.6, and 61.15 of the Colorado Discharge Permit System
Regulations.
3. Special Notifications - Definitions
a. Bypass: The intentional diversion of waste streams from any portion of a treatment facility.
b. Severe Property Damage: Substantial physical damage to property at the treatment facilities which causes them to
become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in
the absence of a bypass. It does not mean economic loss caused by delays in production.
e. Upset: An exceptional incident in which there is unintentional and temporary noncompliance with permit effluent
limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance
to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of
preventative maintenance, or careless or improper operation.
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Permit No. CO -0046663
4. Noncompliance Notification
a. If, for any reason, the permittee does not comply with or will be unable to comply with any discharge limitations or
standards specified in this permit, the permittee shall, at a minimum, provide the Division and EPA with the following
information:
i) A description of the discharge and cause of noncompliance;
ii) The period of noncompliance, including exact dates and times and/or the anticipated time when the discharge will
return to compliance; and
iii) Steps being taken to reduce, eliminate, and prevent recurrence of the noncomplying discharge.
b. The permittee shall report the following circumstances orally within twenty-four (24) hours from the time the permittee
becomes aware of the circumstances, and shall mail to the Division a written report containing the information requested
in Part II.A.4 (a) within five (5) days after becoming aware of the following circumstances:
i) Circumstances leading to any noncompliance which may endanger health or the environment regardless of the cause
of the incident;
ii) Circumstances leading to any unanticipated bypass which exceeds any effluent limitations in the permit;
iii) Circumstances leading to any upset which causes an exceedance of any effluent limitation in the permit;
iv) Daily maximum violations for any of the pollutants limited by Part I.A of this permit and specified as requiring 24 -
hour notification. This includes any toxic pollutant or hazardous substance or any pollutant specifically identified as
the method to control any toxic pollutant or hazardous substance.
c. The permittee shall report instances of non-compliance which are not required to be reported within 24 -hours at the time
Discharge Monitoring Reports are submitted. The reports shall contain the information listed in sub -paragraph (a) of this
section.
5. Other Notification Requirements
Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any
compliance schedule in the permit shall be submitted no later than fourteen (14) days following each scheduled date, unless
otherwise provided by the Division.
The permittee shall notify the Division, in writing, thirty (30) days in advance of a proposed transfer of permit as provided in
Part 11.B.3.
The permittee's notification of all anticipated noncompliance does not stay any permit condition.
All existing manufacturing, commercial, mining, and silvicultural dischargers must notify the Division as soon as they know
or have reason to believe:
a. That any activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any
toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification
levels":
i) One hundred micrograms per liter (100 µg/l);
ii) Two hundred micrograms per liter (200 µg/I) for acrolein and acrylonitrile; five hundred micrograms per liter (500
µg/I) for 2.4-dinitrophenol and 2-methyl-4.6-dinitrophenol; and one milligram per liter (1.0 mg/1) for antimony;
iii) Five (5) times the maximum concentration value reported for that pollutant in the permit application in accordance
with Section 6I.4(2)(g).
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Permit No. CO -0046663
iv) The level established by the Division in accordance with 40 C.F.R. § 122.44(f).
b. That any activity has occurred or will occur which would result in any discharge, on a non -routine or infrequent basis, of
a toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following "notification
levels":
i) Five hundred micrograms per liter (500 gg/I);
ii) One milligram per liter (1 mg/I) for antimony; and
iii) Ten (10) times the maximum concentration value reported for that pollutant in the permit application.
iv) The level established by the Division in accordance with 40 C.F.R. § 122.44(t).
6. Bypass Notification
If the permittee knows in advance of the need for a bypass, a notice shall be submitted, at least ten days before the date of the
bypass, to the Division. The bypass shall be subject to Division approval and limitations imposed by the Division. Violations
of requirements imposed by the Division will constitute a violation of this permit.
7. Upsets
a. Effect of an Upset
An upset constitutes an affirmative defense to an action brought for noncompliance with permit effluent limitations if the
requirements of paragraph (b) of this section are met. No determination made during administrative review of claims that
noncompliance was caused by upset, and before an action for noncompliance, is final administrative action subject to
judicial review.
b. Conditions Necessary for a Demonstration of Upset
A permittee who wishes to establish the affirmative defense of upset shall demonstrate through properly signed
contemporaneous operating logs, or other relevant evidence that:
i) An upset occurred and that the permittee can identify the specific cause(s) of the upset; and
H) The permitted facility was at the time being properly operated and maintained; and
Hi) The permittee submitted proper notice of the upset as required in Part II.A.4. of this permit (24 -hour notice); and
iv) The permittee complied with any remedial measure necessary to minimize or prevent any discharge or sludge use or
disposal in violation of this permit which has a reason able likelihood of adversely affecting human health or the
environment.
In addition to the demonstration required above, a permittee who wishes to establish the affirmative defense of upset for
a violation of effluent limitations based upon water quality standards shall also demonstrate through monitoring,
modeling or other methods that the relevant standards were achieved in the receiving water.
c. Burden of Proof
In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has the burden of proof
8. Discharge Point
Any discharge to the waters of the State from a point source other than specifically authorized by this permit is prohibited.
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9. Proper Operation and Maintenance
The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control including all
portions of the collection system and lift stations owned by the pennittee (and related appurtenances) which are installed or
used by the pennittee as necessary to achieve compliance with the conditions of this permit. Proper operation and
maintenance includes effective performance and adequate laboratory and process controls, including appropriate quality
assurance procedures (40 CFR 122.41(e). This provision requires the operation of back-up or auxiliary facilities or similar
systems which are installed by the permittee only when necessary to achieve compliance with the conditions of the permit.
10. Minimization of Adverse Impact
The pennittee shall take all reasonable steps to minimize or prevent any discharge of sludge use or disposal in violation of
this permit which has a reasonable likelihood of adversely affecting human health or the environment. As necessary,
accelerated or additional monitoring to determine the nature and impact of the noncomplying discharge is required.
11. Removed Substances
Solids, sludges, or other pollutants removed in the course of treatment or control of wastewaters shall be disposed in
accordance with applicable state and federal regulations.
For all domestic wastewater treatment works, at industrial facilities, the permittee shall dispose of sludge in accordance with
all State and Federal regulations.
12. Submission of Incorrect or Incomplete Information
Where the permittee failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit
application or report to the Division, the permittee shall promptly submit the relevant information which was not submitted or
any additional information needed to correct any erroneous information previously submitted.
13. Bypass
a. Bypasses are prohibited and the Division may take enforcement action against the permittee for bypass, unless:
i) The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage;
ii) There were no feasible alternatives to bypass such as the use of auxiliary treatment facilities, retention of untreated
wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate
back-up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a
bypass which occurred during normal periods of equipment downtime or preventive maintenance; and
iii) Proper notices were submitted in compliance with Part II.A.4.
b. "Severe property damage" as used in this Subsection means substantial physical damage to the treatment facilities which
causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be
expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in
production.
c. The permittee may allow a bypass to occur which does not cause effluent limitations to be exceeded, but only if it also is
for essential maintenance or to assure optimal operation. These bypasses are not subject to the provisions of paragraph
(a) above.
d. The Division may approve an anticipated bypass, after considering adverse effects, if the Division determines that the
bypass will meet the conditions specified in paragraph (a) above.
14. Reduction Loss or Failure of Treatment Facility
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The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the effluent limitations of
the permit. Upon reduction, loss, or failure of the treatment facility, the permittee shall, to the extent necessary to maintain
compliance with its permit, control production, control sources of wastewater, or all discharges, until the facility is restored or
an alternative method of treatment is provided. This provision also applies to power failures, unless an alternative power
source sufficient to operate the wastewater control facilities is provided.
It shall not be a defense for a permittee in an enforcement action that it would be necessary to halt or reduce the permitted
activity in order to maintain compliance with the conditions of this permit.
B. RESPONSIBILITIES
1. Inspections and Right to Entry
The permittee shall allow the Division and/or the authorized representative, upon the presentation of credentials:
a. To enter upon the permittee's premises where a regulated facility or activity is located or in which any records are
required to be kept under the terms and conditions of this permit;
b. At reasonable times to have access to and copy any records required to be kept under the terms and conditions of this
permit and to inspect any monitoring equipment or monitoring method required in the permit; and
c. To enter upon the permittee's premises in a reasonable manner and at a reasonable time to inspect and/or investigate, any
actual, suspected, or potential source of water pollution, or to ascertain compliance or non compliance with the Colorado
Water Quality Control Act or any other applicable state or federal statute or regulation or any order promulgated by the
Division. The investigation may include, but is not limited to, the following: sampling of any discharge and/or process
waters, the taking of photographs, interviewing of any person having knowledge related to the discharge permit or
alleged violation, access to any and all facilities or areas within the penmittee's premises that may have any affect on the
discharge, permit, or alleged violation. Such entry is also authorized for the purpose of inspecting and copying records
required to be kept concerning any effluent source.
d. The permittee shall provide access to the Division to sample the discharge at a point after the final treatment process but
prior to the discharge mixing with state waters upon presentation of proper credentials.
In the making of such inspections, investigations, and determinations, the Division, insofar as practicable, may designate as
its authorized representatives any qualified personnel of the Department of Agriculture. The Division may also request
assistance from any other state or local agency or institution.
2. Duty to Provide Information
The permittee shall furnish to the Division, within a reasonable time, any information which the Division may request to
determine whether cause exists for modifying, revoking and reissuing, or terminating this permit, or to determine compliance
with this permit. The permittee shall also furnish to the Division, upon request, copies of records required to be kept by this
permit.
3. Transfer of Ownership or Control
a. Except as provided in paragraph b. of this section, a permit may be transferred by a permittee only if the permit has been
modified or revoked and reissued as provided in Section 61.8(8) of the Colorado Discharge Permit System Regulations,
to identify the new permittee and to incorporate such other requirements as may be necessary under the Federal Act.
b. A permit may be automatically transferred to a new permittee
i) The current permittee notifies the Division in writing 30 days in advance of the proposed transfer date; and
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Permit No. CO -0046663
ii) The notice includes a written agreement between the existing and new permittee(s) containing a specific date for
transfer of permit responsibility, coverage and liability between them; and
iii) The Division does not notify the existing permittee and the proposed new permittee of its intent to modify, or revoke
and reissue the permit.
iv) Fee requirements of the Colorado Discharge Permit System Regulations, Section 61.15, have been met.
4. Availability of Reports
Except for data determined to be confidential under Section 308 of the Federal Clean Water Act and the Colorado Discharge
Permit System Regulations 5 CCR 1002-61, Section 61.5(4), all reports prepared in accordance with the terms of this permit
shall be available for public inspection at the offices of the Division and the Environmental Protection Agency.
The name and address of the permit applicant(s) and pemiittee(s), permit applications, permits and effluent data shall not be
considered confidential. Knowingly making false statement on any such report may result in the imposition of criminal
penalties as provided for in Section 309 of the Federal Clean Water Act, and Section 25-8-610 C.R.S.
5. Modification Suspension Revocation or Termination of Permits By the Division
The filing of a request by the permittee for a permit modification, revocation and reissuance, termination or a notification of
planned changes or anticipated noncompliance, does not stay any permit condition.
a. A permit may be modified, suspended, or terminated in whole or in part during its term for reasons determined by the
Division including, but not limited to, the following:
i) Violation of any terms or conditions of the permit;
ii) Obtaining a permit by misrepresentation or failing to disclose any fact which is material to the granting or denial of a
permit or to the establishment of terms or conditions of the permit; or
iii) Materially false or inaccurate statements or information in the permit application or the permit.
iv) A determination that the permitted activity endangers human health or the classified or existing uses of state waters
and can only be regulated to acceptable levels by permit modifications or termination.
b. A permit may be modified in whole or in part for the following causes, provided that such modification complies with the
provisions of Section 61.10 of the Colorado Discharge Permit System Regulations:
i) There are material and substantial alterations or additions to the permitted facility or activity which occurred after
permit issuance which justify the application of permit conditions that are different or absent in the existing permit.
ii) The Division has received new information which was not available at the time of permit issuance (other than
revised regulations, guidance, or test methods) and which would have justified the application of different permit
conditions at the time of issuance. For permits issued to new sources or new dischargers, this cause includes
information derived from effluent testing required under Section 61.4(7)(e) of the Colorado Discharge Permit
System Regulations. This provision allows a modification of the permit to include conditions that are less stringent
than the existing permit only to the extent allowed under Section 61.10 of the Colorado Discharge Permit System
Regulations.
iii) The standards or regulations on which the permit was based have been changed by promulgation of amended
standards or regulations or by judicial decision after the permit was issued. Permits may be modified during their
terms for this cause only as follows:
(A) The permit condition requested to be modified was based on a promulgated effluent limitation guideline, EPA
approved water quality standard, or an effluent limitation set forth in 5 CCR 1002-62, § 62 et seq.; and
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(B) EPA has revised, withdrawn, or modified that portion of the regulation or effluent limitation guideline on which
the permit condition was based, or has approved a Commission action with respect to the water quality standard
or effluent limitation on which the permit condition was based; and
(C) The permittee requests modification after the notice of final action by which the EPA effluent limitation
guideline, water quality standard, or effluent limitation is revised, withdrawn, or modified; or
(D) For judicial decisions, a court of competent jurisdiction has remanded and stayed EPA promulgated regulations
or effluent limitation guidelines, if the remand and stay concern that portion of the regulations or guidelines on
which the permit condition was based and a request is filed by the pennittee in accordance with this Regulation,
within ninety (90) days of judicial remand.
iv) The Division determines that good cause exists to modify a permit condition because of events over which the
permittee has no control and for which there is no reasonable available remedy.
v) The permittee has received a variance.
vi) When required to incorporate applicable toxic effluent limitation or standards adopted pursuant to § 307(a) of the
Federal act.
vii) When required by the reopener conditions in the permit.
viii) As necessary under 40 C.F.R. 403.8(e), to include a compliance schedule for the development of a pretreatment
program.
ix) When the level of discharge of any pollutant which is not limited in the permit exceeds the level which can be
achieved by the technology -based treatment requirements appropriate to the permittee under Section 61.8(2) of the
Colorado Discharge Permit System Regulations.
x) To establish a pollutant notification level required in Section 61.8(5) of the Colorado Discharge Permit System
Regulations.
xi) To correct technical mistakes, such as errors in calculation, or mistaken interpretations of law made in determining
permit conditions, to the extent allowed in Section 61.10 of the Colorado State Discharge Permit System
Regulations.
xii) When required by a permit condition to incorporate a land application plan for beneficial reuse of sewage sludge, to
revise an existing land application plan, or to add a land application plan.
xiii) For any other cause provided in Section 61.10 of the Colorado Discharge Permit System Regulations.
c. At the request of a permittee, the Division may modify or terminate a permit and issue a new permit if the following
conditions are met:
i) The Regional Administrator has been notified of the proposed modification or termination and does not object in
writing within thirty (30) days of receipt of notification,
ii) The Division finds that the permittee has shown reasonable grounds consistent with the Federal and State statutes
and regulations for such modifications or termination;
iii) Requirements of Section 61.15 of the Colorado Discharge Permit System Regulations have been met, and
iv) Requirements of public notice have been met.
d. Permit modification (except for minor modifications), termination or revocation and reissuance actions shall be subject to
the requirements of Sections 61.5(2), 61.5(3), 61.6, 61.7 and 61.15 of the Colorado Discharge Permit System
Regulations. The Division shall act on a permit modification request, other than minor modification requests, within 180
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days of receipt thereof Except for minor modifications, the terms of the existing permit govern and are enforceable until
the newly issued permit is formally modified or revoked and reissued following public notice.
e. Upon consent by the permittee, the Division may make minor permit modifications without following the requirements of
Sections 61.5(2), 61.5(3), 61.7, and 61.15 of the Colorado Discharge Permit System Regulations. Minor modifications to
permits are limited to:
i) Correcting typographical errors; or
ii) Increasing the frequency of monitoring or reporting by the permittee; or
iii) Changing an interim date in a schedule of compliance, provided the new date of compliance is not more than 120
days after the date specific in the existing permit and does not interfere with attainment of the final compliance date
requirement; or
iv) Allowing for a transfer in ownership or operational control of a facility where the Division determines that no other
change in the permit is necessary, provided that a written agreement containing a specific date for transfer of permit
responsibility, coverage and liability between the current and new permittees has been submitted to the Division; or
v) Changing the construction schedule for a discharger which is a new source, but no such change shall affect a
discharger's obligation to have all pollution control equipment installed and in operation prior to discharge; or
vi) Deleting a point source outfall when the discharge from that outfall is terminated and does not result in discharge of
pollutants from other outfalls except in accordance with permit limits.
f. When a permit is modified, only the conditions subject to modification are reopened. If a permit is revoked and reissued,
the entire permit is reopened and subject to revision and the permit is reissued for a new term.
g. The filing of a request by the permittee for a permit modification, revocation and reissuance or termination does not stay
any permit condition.
h. All permit modifications and reissuances are subject to the antibacksliding provisions set forth in 61.10(e) through (g).
6. Oil and Hazardous Substance Liability
Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any
responsibilities, liabilities, or penalties to which the permittee is or may be subject to under Section 311 (Oil and Hazardous
Substance Liability) of the Clean Water Act.
7. State Laws
Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any
responsibilities, liabilities, or penalties established pursuant to any applicable State law or regulation under authority granted
by Section 510 of the Clean Water Act. Nothing in this permit shall be construed to prevent or limit application of any
emergency power of the division.
8. Permit Violations
Failure to comply with any terms and/or conditions of this permit shall be a violation of this permit. The discharge of any
pollutant identified in this permit more frequently than or at a level in excess of that authorized shall constitute a violation of
the permit. Except as provided in Part I.D and Part II.A or B, nothing in this permit shall be construed to relieve the permittee
from civil or criminal penalties for noncompliance (40 CFR 122.41(a)(1)).
9. Property Rights
The issuance of this permit does not convey any property or water rights in either real or personal property, or stream flows,
or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any
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infringement of Federal, State or local laws or regulations.
10. Severability
The provisions of this permit are severable. If any provisions of this permit, or the application of any provision of this permit
to any circumstance, is held invalid, the application of such provision to other circumstances and the application of the
remainder of this permit shall not be affected.
11. Renewal Application
If the pennittee desires to continue to discharge, a permit renewal application shall be submitted at least one hundred eighty
(180) days before this permit expires. If the permittee anticipates there will be no discharge after the expiration date of this
permit, the Division should be promptly notified so that it can terminate the permit in accordance with Part 'I.R.S.
12. Confidentiality
Any information relating to any secret process, method of manufacture or production, or sales or marketing data which has
been declared confidential by the permittee, and which may be acquired, ascertained, or discovered, whether in any sampling
investigation, emergency investigation, or otherwise, shall not be publicly disclosed by any member, officer, or employee of
the Commission or the Division, but shall be kept confidential. Any person seeking to invoke the protection of this
Subsection (12) shall bear the burden of proving its applicability. This section shall never be interpreted as preventing full
disclosure of effluent data.
13. Fees
The pennittee is required to submit payment of an annual fee as set forth in the 2005 amendments to the Water Quality
Control Act. Section 25-8-502 (I) (b), and the Colorado Discharge Permit System Regulations 5 CCR 1002-61, Section 61.15
as amended. Failure to submit the required fee when due and payable is a violation of the permit and will result in
enforcement action pursuant to Section 25-8-601 et. seq., C.R.S. 1973 as amended.
14. Duration of Permit
The duration of a permit shall be for a fixed term and shall not exceed five (5) years. Filing of a timely and complete
application shall cause the expired permit to continue in force to the effective date of the new permit. The permit's duration
may be extended only through administrative extensions and not through interim modifications.
15. Section 307 Toxics
If a toxic effluent standard or prohibition, including any applicable schedule of compliance specified, is established by
regulation pursuant to Section 307 of the Federal Act for a toxic pollutant which is present in the permittee's discharge and
such standard or prohibition is more stringent than any limitation upon such pollutant in the discharge permit, the Division
shall institute proceedings to modify or revoke and reissue the permit to conform to the toxic effluent standard or prohibition.
16. Effect of Permit Issuance
a. The issuance of a permit does not convey any property rights or any exclusive privilege.
b. The issuance of a permit does not authorize any injury to person or property or any invasion of personal rights, nor does
it authorize the infringement of federal, state, or local laws or regulations.
c. Except for any toxic effluent standard or prohibition imposed under Section 307 of the Federal act or any standard for
sewage sludge use or disposal under Section 405(d) of the Federal act, compliance with a permit during its term
constitutes compliance, for purposes of enforcement, with Sections 301, 302, 306, 318, 403, and 405(a) and (b) of the
Federal act. However, a permit may be modified, revoked and reissued, or terminated during its term for cause as set
forth in Section 61.8(8) of the Colorado Discharge Permit System Regulations.
Permit, Part II
Page 26 of 29
Permit No. CO -0046663
d. Compliance with a permit condition which implements a particular standard for sewage sludge use or disposal shall be an
affirmative defense in any enforcement action brought for a violation of that standard for sewage sludge use or disposal.
Permit, Part III
Page 27 of 29
Permit No. CO -0046663
PART III
CATEGORICAL INDUSTRIES
Aluminum Forming
Asbestos Manufacturing
Battery Manufacturing
Builders' Paper and Board Mills
Canned & Preserved Fruits and Vegetables Processing
Canned & Preserved Seafood Processing
Carbon Black Manufacturing
Cement Manufacturing
Coal Mining
Coil Coating
Copper Forming
Dairy Products Processing
Electrical and Electronic Components
Electroplating
Explosives Manufacturing
Feedlots
Ferroalloy Manufacturing
Fertilizer Manufacturing
Glass Manufacturing
Grain Mills
Gum and Wood Chemicals Manufacturing
Hospital
Ink Formulation
Inorganic Chemicals Manufacturing
Iron and Steel Manufacturing
Leather Tanning and Finishing
Volatiles
acrolein
acrylonitrile
benzene
bromoform
carbon tetrachloride
chlorobenzene
ch lorodibromom ethane
chloroethane
2-chloroethylvinyl ether
chloroform
dichl orobromomethane
1,1-dichlorethane
1,2-dichlorethanc
1,1-dichlorethylene
1,2-dichlorpropane
I ,3-dichlorpropylene
ethylbenzene
methyl bromide
methyl chloride
methylene chloride
Meat Products
Metal Finishing
Metal Molding and Casting (Foundries)
Mineral Mining and Processing
Nonferrous Metals Manufacturing
Nonferrous Metals Forming and Metal Powders
Oil and Gas Extraction
Organic Chemicals, Plastics, and Synthetic Fibers
Ore Mining and Dressing
Paint Formulation
Paving and Roofing Materials (Tars and Asphalt)
Pesticide Chemicals
Petroleum Refining
Pharmaceutical Manufacturing
Phosphate Manufacturing
Photographic
Plastics Molding and Forming
Porcelain Enameling
Pulp, Paper, and Paperboard Manufacturing
Rubber Manufacturing
Soap and Detergent Manufacturing
Steam Electric Power Generating
Sugar Processing
Textile Mills
Timber Products Processing
PRIORITY POLLUTANTS AND HAZARDOUS SUBSTANCES
ORGANIC TOXIC POLLUTANTS IN EACH OF FOUR FRACTIONS
IN ANALYSIS BY GAS CHROMATOGRAPHY/MASS SPECTROSCOPY (GC/MS)
Base/Neutral
acenaphthene
acenaphthylene
anthracene
benzidine
benzo(a)anthracene
benzo(a)pyrene
3,4-benzofluomnthene
benzo(ghi)perylene
benzo(k)fluoranthene
bis(2-chloroethoxy)methane
bis(2-chloroethyl)ether
bis(2-chloroisopropyl)ether
bis(2-ethylhexyl)phthalate
4-bromophenyl phenyl ether
butylbenzyl phthalate
2-chloronaphthalcnc
4-chlorophenyl phenyl ether
chrysene
dibenzo(a,h)anthracene
1,2-dichlorobenzene
Acid Compounds Pesticides
2-chlorophenol
2,4-dichlorophenol
2,4,-dimethylphenol
4,6-dinitro-o-cresol
2,4-dinitrophenol
2-nitrophenol
4-nitrophenol
p-chloro-m-cresol
pentachlorophenol
phenol
2,4,6-trichlorophenol
aldrin
alpha -BBC
beta-BHC
gamma-BHC
delta-BHC
chlordane
4,4' -DDT
4,4'-DDE
4,4'-DDD
dieldrin
alpha-endosulfan
beta-cndosulfan
endosulfan sulfate
endrin
endrin aldehyde
heptachlor
heptachlor epoxide
PCB -I242
PCB -1254
PCB -1221
Permit, Part III
Page 28 of 29
Permit No. CO -0046663
PRIORITY POLLUTANTS AND HAZARDOUS SUBSTANCES
ORGANIC TOXIC POLLUTANTS IN EACH OF FOUR FRACTIONS
IN ANALYSIS BY GAS CHROMATOGRAPHY/MASS SPECTROSCOPY (GC/MS)
Volatiles
1,1,2,2-tetrachloroethane
tetrachloroethylene
toluene
1,2-trans-dichloroethylene
1,1,1-trichloroethane
1,1,2-trichloroethane
trichloroethylene
vinyl chloride
Base/Neutral Acid Compounds
1,3-dichlorobenzene
1,4-dichlorobenzene
3,3-dichlorobenzidine
diethyl phthalate
dimethyl phthalate
di -n -butyl phthalate
2,4-dinitrotoluene
2,6-dinitrotoluene
di-n-octyl phthalate
I ,2-diphenylhydrazine (as azobenzene)
fluorene
fluoranthene
hexachlorobenzene
hexachlorobutadiene
hexachlorcyclopentadiene
hexachloroethane
indeno(I,2,3-ed)pyrene
isophorone
naphthalene
nitrobenzene
N -n i trosodimethy l am i ne
N-nitrosodi-n-propylamine
N-nitrosodiphenylamine
l amine
phenanthrenc
pyrcne
1,2,4-tichlorobenzene
OTHER TOXIC POLLUTANTS
(METALS AND CYANIDE) AND TOTAL PHENOLS
Antimony, Total
Arsenic, Total
Beryllium, Total
Cadmium, Total
Chromium, Total
Copper, Total
Lead, Total
Mercury, Total
Nickel, Total
Selenium, Total
Silver, Total
Thallium, Total
Zinc, Total
Cyanide. Total
Phenols, Total
Pesticides
PCB -I 232
PCB -I248
PCB -1260
PCB -1016
toxaphene
Permit, Part HI
Page 29 of 29
Permit No. CO -0046663
TOXIC POLLUTANTS AND HAZARDOUS SUBSTANCES
REQUIRED TO BE IDENTIFIED BY EXISTING DISCHARGERS
IF EXPECTED TO BE PRESENT
Toxic Pollutants
Asbestos
Hazardous Substances
Acetaldehyde
Allyl alcohol
Ally] chloride
Amyl acetate
Aniline
Benzonitrile
Benzyl chloride
Butyl acetate
Butylamine
Captan
Carbaryl
Carbofuran
Carbon disulfide
Chlorpyrifos
Coumaphos
Cresol
Crotonaldehyde
Cyclohexane
2,4-D(2,4-Dichlorophenoxy acetic acid)
Diazinon
Dicamba
Dichlobenil
Dichlone
2,2-Dichloropropionic acid
Dichlorvos
Diethyl amine
Dimethyl amine
Dinitrobenzene
Diquat
Disulfoton
Diuron
Epichlorohydrin
Ethanolamine
Ethion
Ethylene diamine
Ethylene dibromide
Formaldehyde
Furfural
Guthion
Isoprene
Isopropanolamine
Keithane
Kepone
Malathion
Mercaptodimethur
Mcthoxychlor
Methyl mercaptan
Methyl methacrylate
Methyl parathion
Mexacarbate
Monoethyl amine
Monomethyl amine
Naled
Napthenic acid
Nitrotoluene
Parathion
Phenolsulfanate
Phosgene
Propargite
Propylene oxide
Pyrethrins
Quinoline
Resorcinol
Strontium
Strychnine
Styrene
TDE (Tetrachlorodiphenylethane)
2,4,5-T (2,4,5-Trichlorophenoxy acetic acid)
2,4,5-TP [2-(2,4,5-Trichlorophenoxy) propanoic acid]
Trichlorofan
Triethylamine
Trimethylamine
Uranium
Vandium
Vinyl Acetate
Xylene
Xylenol
Zirconium
PUBLIC NOTICE SHEET
Town of Berthoud. James J. White, Town Administrator, 328 Massachusetts
Avenue, Berthoud, CO, 80513, PHONE: 970-532-2643; PERMIT NO.: CO -0046663;
Weld County.
First Renewal
DRAFTER: Kenan Diker
DISCHARGE: To the Little Thompson River.
COLORADO DISCHARGE PERMIT SYSTEM (CDPS)
FACT SHEET FOR PERMIT NUMBER CO -0046663
TOWN OF BERTHOUD, WELD COUNTY
TABLE OF CONTENTS
I. TYPE OF PERMIT I
II. FACILITY INFORMATION
III. RECEIVING STREAM 2
IV. FACILITIES EVALUATION 2
V. PERFORMANCE HISTORY 3
VI. TERMS AND CONDITIONS OF PERMIT 5
VII. REFERENCES 15
VIII. PUBLIC NOTICE COMMENTS 16
1. TYPE OF PERMIT
Domestic Major, POTW, 1t5 Renewal, Surface Water
II. FACILITY INFORMATION
A. Facility Type:
Fee Category:
Category Flow Range:
Annual Fee:
B. SIC Code:
Facility Classification:
Domestic -Major Municipal, Mechanic
Domestic wastewater - mechanical plants, Category 21, Subcategory 6
Sewage from 1,000,000 up to 2,499,999 gpd
$6090 effective July 1, 2007
4952 Sewerage Systems,
Class B per Section 100.5.2 of the Water and Wastewater Facility
Operator Certification Requirements
C. Legal Contact/Permittee: James J. White, Town Administrator,
328 Massachusetts Avenue, Berthoud, CO, 80513
970-532-2643
Facility Contact:
Facility Location:
Certified Operator:
D. Discharge Point:
E. Facility Flows:
Robert Airhart
970-532-2412
20213 WCR #1, Berthoud, CO, 80513, Latitude: 40°17'00 " N, Longitude:
105°04'00" W
Robert Airhart, Classification A
Outfall 00IA, following disinfection and prior to discharge to the Little
Thompson River.
2 MGD
ISSUED
EFFECTIVE EXPIRATION
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 2, Permit No. CO -0046663
F. Major Changes From Last Renewal:
The new ammonia standards have been incorporated into this permit.
Monitoring for most metals has been eliminated in this renewal, however, limitations for mercury and
cyanide will be required and a compliance schedule has been added to the permit to allow the permittee
time to ensure that these limitations can be met.
HI. RECEIVING STREAM
A. Waterbody Identification: COSPBT09, the Little Thompson River
B. Water Quality Assessment:
An assessment of the stream standards, low flow data, and ambient stream data has been performed to
determine the assimilative capacities for the Little Thompson River for potential pollutants of concern. This
information, which is contained in Appendix A to this rationale, also includes an antidegradation review,
where appropriate. The Division's Permits Section has reviewed the assimilative capacities to determine the
appropriate water quality -based effluent limitations as well as potential limits based on the antidegradation
evaluation, where applicable. The limitations based on the assessment and other evaluations conducted as
part of this rationale can be found in Part I.A of the permit.
Outfall 001A will continue to be the authorized discharge point to the receiving stream.
IV. FACILITIES EVALUATION
A. Infiltration/Inflow (I/I)
No infiltration/inflow problems have been documented in the service area.
B. Lift Stations
Table IV -1 summarizes the information provided in the renewal application for the lift stations in the
service area.
Table IV -1 — Lift Station Summary
Station Firm Pump
Name/# Capacity (gpm)
Peak Flows (gpd)*
% Capacity,
(based on
peak flow)
Campion 2@250
Bo -Mar 2@100
Hillsdale 2@350
Mary's Farm 2@75
250,000
3,000
13,000
8,000
69.4
2.0
2.6
7.4
C. Treatment Facility
The facility consists of two conventional activated sludge, two secondary clarifiers and low pressure
high output UV disinfection for wastewater treatment. The permittee has not performed any
construction at this facility that would change the hydraulic capacity of 2 MGD or the organic capacity
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 3, Permit No. CO -0046663
of 3900 lbs BOD5/day, which were specified in Site Approval #4694. That document should be referred
to for any additional information.
D. Biosolids Treatment and Disposal
Biosolids are treated in an aerobic digester. Dewatered biosolids are then hauled for land application.
Town also has options for composting and landfilling of biosolids.
I. EPA General Permit
EPA Region 8 issued a General Permit (effective October 19, 2007) for Colorado facilities whose
operations generate, treat, and/or use/dispose of sewage sludge by means of land application,
landfill, and surface disposal under the National Pollutant Discharge Elimination System. All
Colorado facilities are required to apply for and to obtain coverage under the EPA General Permit.
2. Biosolids Regulation (Regulation No. 64, Colorado Water Quality Control Commission)
While the EPA is now the issuing agency for biosolids permits, Colorado facilities that land apply
biosolids must comply with requirements of Regulation No. 64, such as the submission of annual
reports as discussed later in this rationale.
V. PERFORMANCE HISTORY
A. Monitoring Data
1. Discharge Monitoring Reports - Table V-1 summarizes the effluent data reported on the monthly
Discharge Monitoring Reports (DMRs) for the Town of Berthoud WWTF from November 2004
through January 2009.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 4, Permit No. CO -0046663
Table
115at�rpks .. Reported .wemge Reported Maximum Previous Number of
Concentrations , Concentrations .:;;.;: Limit
Parotrrefer . ;; o► C_Avg�M�xllD`:`
Reporting •
Avg/Min/Max :.::.: ° ..AirgfMitF/�4tgx::.. .:::P'tlaeit G11 ; ; Excurs
Periods
Influent Flow (MGD)
24
20/0.4/470
0.6/0.46/0.82
Report/Report
0
Effluent Flow (MGD)
24
0.46/0.36/0.56
0.55/0.4/0.75
2/Report
0
pH (su)
24
6.9/6.5/7.3
7.7/7.1/8.8
6.5 -9
0
Fecal Coliform (#/100 ml)
24
5.6/1/115
8.5/1/304
200/400
0
TRC (mg/1)
20
0/0/0
0/0/0
0.011/0.019
0
N113, Tot (mg/1) Jan
5
0.53/0.06/1.5
3.1/0.1/8.3
Report/19
0
NH3, Tot (mg/I) Feb
5
0.29/0.05/0.65
1.1/0.1/3.8
20/20
0
N113, Tot (mg/1) Mar
5
0.61/0.02/2.7
3.2/0.02/16
17/18
0
NH3, Tot (mg/1) Apr
4
0.11/0.02/0.21
0.17/0.03/0.4
12/18
0
NH3, Tot (mg/1) May
4
0.31/0.1/0.88
1.2/0.1/3.7
12/18
0
NH3, Tot (mg/1) Jun
4
0.098/0.03/0.18
0.42/0.04/0.9
12/18
0
NH3, Tot (mg/1) Jul
4
0.1/0.03/0.21
0.14/0.1/0.19
12/18
0
NH3, Tot (mg/1) Aug
4
0.13/0.06/0.24
0.29/0.09/0.8
9.3/17
0
NH3, Tot (mg/1) Sep
5
0.89/0.09/3.3
3/0.1/15
9.4/18
0
N113, Tot (mg/I) Oct
5
0.16/0.02/0.4
0.53/0.03/1.8
13/18
0
NH3, Tot (mg/1) Nov
5
0.25/0.01/0.98
1.6/0.02/7.3
18/19
0
N113, Tot (mg/1) Dec
5
0.32/0.01/1
1/0.03/4
Report/19
0
BOAS, effluent (mg/1)
24
2.7/1.4/6
3.8/1.9/11
NA/NA/
0
CB0D5, effluent (lbs/day)
24
868/2.5/1864
1127/3.8/2613
NA/NA/
0
CBODS (% removal)
24
98/95/99
NA/NA/NA
NA/NA/
0
TSS (mg/i)
24
6.5/3.3/9.8
9.3/4.4/15
NA/NA/
0
TSS, influent (mg/1)
24
390/272/541
517/326/790
NA/NA/
0
TSS, effluent (mg/1)
24
6.5/3.3/9.8
9.3/4.4/15
30/45/
0
TSS (% removal)
24
98/95/99
NA/NA/NA
NA/NA/
0
As, TR (pg/1)
8
0.6/0/2
0.6/0/2
NA/Report
0
Cd, Dix (pg/1)
9
0.077/0/0.5
0.077/0/0.5
Report/Report
0
Cr+3, Dis (pg/1)
9
2.2/<10/10
2.2/<10/10
Report/Report
0
Cr+6, Dis (pg/1)
8
2.51<10/10
2.5/<10/10
Report/Report
0
Cu, Dis (pg/I)
8
16/9.9/23
16/9.9/23
Report/Report
0
CN Free (pg/1)
8
5/0/20
5/0/20
Report/NA
0
Fe, TR (pg/1)
8
44/0/165
49/0/165
Report/NA
0
Ph, Dis (pg/I)
9
0.25/0/1.1
0.25/0/1.1
Report/NA
0
Mn. Dis (pg/1)
9
19/5.2/55
19/5.2/55
Report/NA
0
Hg. Tot (pg/I)
9
0.044/0/0.2
0.044/0/0.2
Report/Report
0
Ni, Dis (pg/1)
9
2.4/0/5.5
2.4/0/5.5
Report/NA
0
Se, Dis (pg/1)
9
0.73/0/3
0.73/0/3
NA/Report
0
Ag, Dis (pg/1)
9
0.0067/0/0.03
0.0067/0/0.03
Report/Report
0
Zn. Dis (pg/1)
9
48/4.3/68
48/4.3/68
Report/Report
0
WET, chronic
pimephales lethality, Stat Diff
17
//
100/100/100
100
0
pimephales lethality, 1C25
17
//
100/100/100
0
ceriodaphnia lethality, Stat Diff
17
//
100/100/100
100
0
ceriodaphnia lethality, 1C25
17
//
100/100/100
0
pimephales toxicity, Stat Dff
17
//
94/25/100
Report
0
pimephales toxicity, IC25
17
//
98/58/100
0
ceriodaphnia toxicity, Stat Diff
17
II
90/25/100
Report
0
ceriodaphnia toxicity, 1C25
17
//
88/15/100
0
* This is a facility capacity
** Geometric mean
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 5, Permit No. CO -0046663
NA means Not Applicable
B. Compliance With Terms and Conditions of Previous Permit
1. Effluent Limitations — The data shown in the preceding table(s) indicate that the Town of Berthoud
facility has maintained compliance with the previous permit.
The permittee has been in apparent compliance with all other numerical limitations of the permit.
VI. TERMS AND CONDITIONS OF PERMIT
A. Discussion of Effluent Limitations
1. Technology Based Limitations
a. Federal Effluent Limitation Guidelines — There are no existing Federal Effluent Limitation
Guidelines for domestic wastewater treatment facilities.
b. Regulation 62: Regulations for Effluent Limitations — These Regulations include effluent
limitations that apply to all discharges of wastewater to State waters. These regulations are
applicable to the discharge from the Town of Berthoud WWTF.
i. BOD5 and TSS - The BOD5 and TSS concentrations are the most stringent effluent limits and
arc therefore applied. The removal percentages for BOD5 and TSS also apply based on the
Regulations for Effluent Limitations. In the previous permit, CBOD5 limits were imposed in
lieu of the BOD5 limits pursuant to the facility's request and in accordance with Section
62.4(6) of the regulations. However, the facility now requests BOD5 limits to be applied in
renewed permit. These limitations are the same as those contained in the previous permit and
are imposed effective immediately.
ii. Oil and Grease — The oil and grease limitations from the Regulations for Effluent Limitations
are applied as they are the most stringent limitations. These limitations are the same as those
contained in the previous permit and are imposed effective immediately.
iii. The pH and total residual chlorine concentrations specified in the Regulations for Effluent
Limitations are not the most stringent and thus are not used as discussed below.
2. Water Quality Regulations and Guidance Documents
a. Water Quality Assessment — The WQA in Appendix A contains the evaluation of pollutants
limited by water quality standards. The mass balance equation shown in Section IV of Appendix
A was used for most pollutants to calculate the maximum allowable effluent concentration, M2,
that could be discharged without causing the water quality standard to be violated. For
ammonia, the AMMTOX Model was used to determine the maximum assimilative capacity of
the receiving stream. A detailed discussion of the calculations for the maximum allowable
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 6, Permit No. CO -0046663
concentrations for E. coli, fecal coliform, total residual chlorine, ammonia, and metals and
cyanide is provided in Section IV of the water quality assessment contained in Appendix A.
The maximum allowable effluent pollutant concentrations determined as part of these
calculations represent the calculated effluent limits that would be protective of water quality.
These are also known as the water quality -based effluent limits (WQBELs). Both acute and
chronic WQBELs may be calculated based on acute and chronic standards, and these may be
applied as daily maximum (acute) or 30 -day average (chronic) limits
b. Antidegradation - Since the receiving water is Use Protected an antidegradation review is not
required pursuant to Section 31.8(2)(b) of The Basic Standards and Methodologies for Surface
Water.
c. Determination of Total Maximum Daily Loads (TMDLs) — The receiving stream to which the
Town of Berthoud WWTF discharges is currently listed on the State's 303(d) list for
development of TMDLs for Cu, Se, E. coli, Aquatic Life Use. However, the TMDL has not yet
been finalized. Although this permit establishes limits for these pollutants, they do not represent
the TMDLs and waste load allocations, and are therefore subject to change upon finalization of
an approved TMDL for this segment.
d. Colorado Mixing Zone Regulations — Pursuant to section 31.10 of The Basic Standards and
Methodologies for Surface Water, a mixing zone determination is required for this permitting
action. The Colorado Mixing Zone Implementation Guidance, dated April 2002, identifies the
process for determining the meaningful limit on the area impacted by a discharge to surface
water where standards may be exceeded (i.e., regulatory mixing zone). This guidance document
provides for certain exclusions from further analysis under the regulation, based on site -specific
conditions.
The guidance document provides a mandatory, stepwise decision -making process for
determining if the permit limits will not be affected by this regulation. Exclusion, based on
Extreme Mixing Ratios, may be granted if the ratio of the design flow to the chronic low flow
(30E3) is greater than 2:1. Since the ratio of the design flow to the chronic low flow is 3.1:0, the
permittee is eligible for an exclusion from further analysis under the regulation.
e. Reasonable Potential Analysis - Using the assimilative capacities contained in the WQA, an
analysis must be performed to determine whether to include the calculated assimilative
capacities as WQBELs in the permit. This reasonable potential (RP) analysis is based on the
Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS
Permits Based on Reasonable Potential, dated December, 2002. This guidance document utilizes
both quantitative and qualitative approaches to establish RP depending on the amount of
available data.
A qualitative determination of RP may be made where ancillary and/or additional treatment
technologies are employed to reduce the concentrations of certain pollutants. However, absent
limitations, a facility may no longer continue such pollutant reductions and therefore the
discharge would result in RP. For this reason, the Permits Section may make a qualitative
determination that absent effluent limitations, there is RP for these pollutants to cause or
contribute to exceedances of water quality standards. This may apply to E. coli, ammonia, total
residual chlorine, nitrate, or total inorganic nitrogen.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 7, Permit No. CO -0046663
To conduct a quantitative RP analysis, a minimum of 10 effluent data points from the previous 5
years, should be used. The equations set out in the guidance for normal and lognormal
distribution, where applicable, are used to calculate the maximum estimated pollutant
concentration (MEPC). For data sets with non -detect values, and where at least 30% of the data
set was greater than the detection level, MDLWIN software is used consistent with Division
guidance to generate the mean and standard deviation, which are then used to establish the
multipliers used to calculate the MEPC. If the MDLWIN program cannot be used the Division's
guidance prescribes the use of best professional judgment.
For some parameters, recent effluent data or an appropriate number of data points may not be
available, or collected data may be in the wrong form (dissolved vs total) and therefore may not
be available for use in conducting a RP analysis. Thus, consistent with Division procedures,
monitoring will be required to collect samples to support a RP analysis and subsequent decisions
for a numeric limit. Samples requirements will be listed at a MON outfall, and all results shall
be reported on a DMR. A compliance schedule may be added to the permit for the request of a
RP analysis once the appropriate data have been collected.
For other parameters, effluent data may be available to conduct a quantitative analysis, and
therefore a RP analysis will be conducted to determine if there is RP for the effluent discharge to
cause or contribute to exceedances of ambient water quality standards. The guidance specifies
that if the MEPC exceeds the maximum allowable pollutant concentration (MAPC), limits must
be established and where the MEPC is greater than half the MAPC (but less than the MAPC),
monitoring must be established. Table VI -1 contains the calculated MEPC compared to the
corresponding MAPC, and the results of the reasonable potential evaluation, for those
parameters that met the data requirements. The RP determination is discussed for each
parameter in the text below.
3. Pollutants Limited by Water Quality Standards
pH — This parameter is limited by the water quality standards of 6.5-9.0 s.u., as this range is
more stringent than the range specified under the Regulations for Effluent Limitations. This
limitation is the same as that contained in the previous permit and is imposed effective immediately.
Escherichia Coli — This is a new parameter for the facility. A qualitative determination of RP has
been made as the WWTF is designed to treat for this parameter. Fecal coliform data indicates that
the facility can meet this new E. coli limitation and it is therefore effective immediately.
Total Residual Chlorine - A qualitative determination of RP has been made as the treatment facility
may use chlorine for disinfection. Previous monitoring as shown in Table V-1 shows that this
limitation can be met and is therefore effective immediately.
Total Arsenic — The RP analysis was based on the WQBEL as described in Appendix A (WQA). A
qualitative analysis was conducted as there was not enough data (less than 10 data point) to conduct
a quantitative RP analysis for 30 -day maximum. Effluent values were as high as 2.0 ug/1. This value
is significantly lower than the WQBEL of 100 ug/l, therefore, the qualitative RP analysis resulted in
determination of no RP for this parameter. Monitoring is not required.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 8, Permit No. CO -0046663
-1 — Reasonable Potential Analysis
30 -Day Average
7 -Day Ave or Daily Max
Parameter
MEPC
WQBEL
(MAPC)
Reasonable
Potential
MEPC
WQBEL
(MAPC)
Reasonable
Potential
E. coli (#/100 ml)
NA
126
Yes (Qual)
NA
252
Yes (Qual)
TRC (mg/I)
0
0.011
Yes (Qual)
0
0.019
Yes (Qual)
NH3, Tot (mg/I)
10
2.8
Yes
21
22
Monitor
NH3, Tot (mg/I) Jan
1.5
5.5
Yes (Qual)
8.3
28
Yes (Qual)
NH3, Tot (mg/I) Feb
0.65
6
Yes (Qual)
3.8
32
Yes (Qual)
NH3, Tot (mg/I) Mar
2.7
5.4
Yes (Qual)
16
31
Yes (Qual)
NH3, Tot (mg/I) Apr
0.21
4.9
Yes (Qual)
0.4
28
Yes (Qual)
NH3, Tot (mg/I) May
0.88
4.7
Yes (Qual)
3.7
33
Yes (Qual)
NH3, Tot (mg/I) Jun
0.18
3.7
Yes (Qual)
0.9
38
Yes (Qual)
NH3, Tot (mg/I) Jul
0.21
2.8
Yes (Qual)
0.19
22
Yes (Qual)
NH3, Tot (mg/I) Aug
0.24
3.3
Yes (Qual)
0.8
30
Yes (Qual)
NH3, Tot (mg/p Sep
3.3
3.7
Yes (Qual)
15
33
Yes (Qual)
NH3, Tot (mg/I) Oct
0.4
3.7
Yes (Qual)
1.8
26
Yes (Qual)
NH3, Tot (mg/q Nov
0.98
4.8
Yes (Qual)
7.3
30
Yes (Qual)
NH3, Tot (mg/I) Dec
1
5.7
Yes (Qual)
4
32
Yes (Qual)
As, TR (µg/1)
2
100
No (Qual)
Cd, Dis (µg/I)
0.5
6.2
No (Qual)
0.5
19
No (Qual)
Cr+3, Dis (µg/1)
10
231
No (Qual)
10
1773
No (Qual)
Cr+6, Dis (µg/I)
10
11
Monitor
10
16
Monitor
Cu, Dis (µg/I)
23
29
Monitor
23
50
Monitor
CN, Frcc (µg/p
20
5
Yes (Qual)
Fc, TR (µg/1)
165
1000
No (Qual)
Pb, Dis (µg/I)
1.1
11
No (Qual)
1.1
281
No (Qual)
Mn, Dis (µg/I)
55
2618
No (Qual)
55
4738
No (Qual)
Hg, Tot (µg/I)
0.2
0.01
Yes (Qual)
Ni, Dis (µg/I)
5.5
168
No (Qual)
5.5
1513
No (Qual)
Se, Dis (µg/I)
3
4.6
Monitor
3
18
No (Qual)
Ag, Dis (µg/l)
0.03
3.5
No (Qual)
0.03
22
No (Qual)
Zn, Dis (µg/I)
68
382
No (Qual)
68
379
No (Qual)
Dissolved Cadmium — The RP analysis was based on the WQBEL as described in Appendix A
(WQA). A qualitative analysis was conducted as there was not enough data (less than 10 data point)
to conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 0.5 ug/I. Since this value is significantly lower than the WQBEL of 6.0 ug/1 and 19
ug/1, respectively for 30 -day maximum and daily maximum, qualitative RP analysis resulted in a
determination of no RP for this parameter. Monitoring is not required.
Dissolved Trivalent Chromium — The RP analysis was based on the WQBEL as described in
Appendix A (WQA). A qualitative analysis was conducted as there was not enough data (less than
10 data point) to conduct a quantitative RP analysis for both 30 -day maximum and daily maximum.
Effluent values were as high as 10 ug/1. Since this value is significantly lower than the WQBEL of
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 9, Permit No. CO -0046663
231 ugh and1773 ug/1, respectively for 30 -day maximum and daily maximum, qualitative RP
analysis resulted in a determination of no RP for this parameter. Monitoring is not required.
Dissolved Hexavalent Chromium — The RP analysis was based on the WQBEL as described in
Appendix A (WQA). A qualitative analysis was conducted as there was not enough data (less than
10 data point) to conduct a quantitative RP analysis for both 30 -day maximum and daily maximum.
Effluent values were as high as 10 ug/l. Because this value is smaller than the WQBEL of 11.0 ug/1
and 16 ug/1, respectively for 30 -day maximum and daily maximum, a qualitative determination of no
RP has been made. Because the detected value is greater than '/ the WQBEL monitoring is required
for this parameter in order to gather data that will be sufficient for a more accurate RP analysis to be
completed.
Dissolved Copper — The RP analysis was based on the WQBEL as described in Appendix A (WQA).
A qualitative analysis was conducted as there was not enough data (less than 10 data point) to
conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 22.6 ug/I. Because this value is smaller than the WQBEL of 29 ug/1 and 50 ug/l,
respectively for 30 -day maximum and daily maximum, a qualitative determination of no RP has
been made. Because the detected value is greater than Y of the WQBEL and the stream is listed as
impaired, monitoring is required for this parameter in order to gather data that will be sufficient for a
more accurate RP analysis to be completed and for development of the TMDL.
Cyanide - The RP analysis was based on the WQBEL as described in Appendix A (WQA). A
qualitative analysis was conducted as there was not enough data (less than 10 data point) to conduct
a quantitative RP analysis for daily maximum. Effluent values were as high as 20 ug/1. Since this
value is greater than the WQBEL of 5 for daily maximum, a qualitative determination of RP has
been made and a limitation for cyanide will be required. As the facility may not be able to meet the
limitation immediately, a compliance schedule will be added to the permit to allow time to meet this
new limitation.
Total Recoverable Iron - The RP analysis was based on the WQBEL as described in Appendix A
(WQA). A qualitative analysis was conducted as there was not enough data (less than 10 data point)
to conduct a quantitative RP analysis for both 30 -day maximum. Effluent values were as high as 165
ug/1. Since this value is significantly lower than the WQBEL of 1000 ug/1 for 30 -day maximum,
qualitative RP analysis resulted in determination of no RP for this parameter. Monitoring is not
required.
Dissolved Lead - The RP analysis was based on the WQBEL as described in Appendix A (WQA). A
qualitative analysis was conducted as there was not enough data (less than 10 data point) to conduct
a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values were as
high as 1.1 ug/1. Since this value is significantly lower than the WQBEL of 11 ug/1 and 281 ug/1,
respectively for 30 -day maximum and daily maximum, qualitative RP analysis resulted in
determination of no RP for this parameter. Monitoring is not required.
Dissolved Manganese - The RP analysis was based on the WQBEL as described in Appendix A
(WQA). A qualitative analysis was conducted as there was not enough data (less than 10 data point)
to conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 55 ug/I. Since this value is smaller than the WQBEL of 2618 ug/l and 4738 ug/1,
respectively for 30 -day maximum and daily maximum, the qualitative RP analysis resulted in a
determination of no RP for this parameter. Monitoring is not required.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 10, Permit No. CO -0046663
Total Mercury - The RP analysis was based on the WQBEL as described in Appendix A (WQA). A
qualitative analysis was conducted as there was not enough data (less than 10 data point) to conduct
a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values were as
high as 0.2 ug/1. This value is greater than the WQBEL of 0.01 ug/1 for 30 -day maximum, a
qualitative determination of RP has been made and a limitation for mercury will be required. As the
facility may not be able to meet the limitation immediately, a compliance schedule will be added to
the permit to allow time to meet this new limitation.
Dissolved Nickel - The RP analysis was based on the WQBEL as described in Appendix A (WQA).
A qualitative analysis was conducted as there was not enough data (less than 10 data point) to
conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 5.5 ug/I. Since this value is significantly lower than the WQBEL of 168 ug/l and
1513 ug/l, respectively for 30 -day maximum and daily maximum, qualitative RP analysis resulted in
determination of no RP for this parameter. Monitoring is not required.
Dissolved Selenium - The RP analysis was based on the WQBEL as described in Appendix A
(WQA). A qualitative analysis was conducted as there was not enough data (less than 10 data point)
to conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 3 ug/I. Because this value is smaller than the WQBEL of 4.6 ug/1 and 18 ug/1,
respectively for 30 -day maximum and daily maximum, a qualitative determination of no RP has
been made. Because the detected value is greater than / the WQBEL and the segment is listed as
impaired, monitoring is required for this parameter in order to gather data that will be sufficient for a
more accurate RP analysis to be completed and for development of the TMDL.
Dissolved Silver - The RP analysis was based on the WQBEL as described in Appendix A (WQA).
A qualitative analysis was conducted as there was not enough data (less than 10 data point) to
conduct a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values
were as high as 0.03 ug/l. Since this value is significantly lower than the WQBEL of 3.5 ug/l and 22
ug/1, respectively for 30 -day maximum and daily maximum, qualitative RP analysis resulted in
determination of no RP for this parameter. Monitoring is not required.
Dissolved Zinc - The RP analysis was based on the WQBEL as described in Appendix A (WQA). A
qualitative analysis was conducted as there was not enough data (less than 10 data point) to conduct
a quantitative RP analysis for both 30 -day maximum and daily maximum. Effluent values were as
high as 68 ug/l. Since this value is significantly lower than the WQBEL of 382 ug/I and 379 ug/1,
respectively for 30 -day maximum and daily maximum, qualitative RP analysis resulted in
determination of no RP for this parameter. Monitoring is not required.
Temperature- As the facility discharges to a receiving stream with a 0 low flow in all months, the
temperature limitations are not applied in this permit.
Organics — The effluent is not expected or known to contain organic chemicals, and therefore,
limitations for organic chemicals are not needed in this permit.
4. Metal Speciation
Until recently there has not been an effective method for monitoring low-level total mercury
COLORADO DEPARTMENT OF HEALTH. Water Quality Control Division
Rationale - Page 11, Permit No. CO -0046663
concentrations in either the receiving stream or the facility effluent. Monitoring for total mercury has
been accomplished as part of past permit conditions and analytical results have all been found at less
than detectable levels. However, detection levels only as low as 0.2 ug/1 have been achieved, versus
a total mercury limit of 0.011 ug/1. To ensure that adequate data are gathered to determine
reasonable potential and consistent with Division initiatives for mercury, quarterly effluent
monitoring for total mercury at low-level detection methods will be required by the permit.
For metals with aquatic life -based dissolved standards, effluent limits and monitoring requirements
are typically based upon the potentially dissolved method of analysis, as required under Regulation
31, Basic Standards and Methodologies for Surface Water. Thus, effluent limits and/or monitoring
requirements for hexavalent chromium, copper, and selenium will be prescribed as the "potentially
dissolved" form.
For cyanide, the acute standard is in the form of "free" cyanide concentrations. However, there is no
analytical procedure for measuring the concentration of free cyanide in a complex effluent.
Therefore, ASTM (American Society for Testing and Materials) analytical procedure D2036-81,
Method C, will be used to measure weak acid dissociable cyanide in the effluent. This analytical
procedure will detect free cyanide plus those forms of complex cyanide that are most readily
converted to free cyanide.
For hexavalent chromium, samples must be unacidified. Accordingly, dissolved concentrations will
be measured rather than potentially dissolved concentrations.
5. Whole Effluent Toxicity (WET) Testing - For this facility, a chronic WET testing is required. (See
Part I.B.6. of the permit).
a. Purpose of WET Testing — The Water Quality Control Division has established the use of WET
testing as a method for identifying and controlling toxic discharges from wastewater treatment
facilities. WET testing is being utilized as a means to ensure that there are no discharges of
pollutants "in amounts, concentrations or combinations which are harmful to the beneficial uses
or toxic to humans, animals, plants, or aquatic life" as required by Section 31.11 (1) of the Basic
Standards and Methodologies for Surface Waters.
b. In -Stream Waste Concentration (IWC) — Where monitoring or limitations for WET are deemed
appropriate by the Division, chronic in -stream dilution as represented by the chronic IWC is
critical in determining whether acute or chronic conditions shall apply. According to the
Colorado Water Quality Control Division Biomonitoring Guidance Document, dated July 1,
1993, for those discharges where the chronic IWC is greater than 9.1% and the receiving stream
has a Class 1 Aquatic Life use or Class 2 Aquatic Life use with all of the appropriate aquatic life
numeric standards, chronic conditions apply. Where the chronic IWC is less than or equal to 9.1,
or the stream is not classified as described above, acute conditions apply. The chronic IWC is
determined using the following equation:
IWC = [Facility Flow (FF)/(Stream Chronic Low Flow (annual) + FF)] X 100%
The flows and corresponding IWC for the appropriate discharge point are:
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page /2, Permit No. CO -0046663
Discharge Chronic Low Flow,
Point 30E3, (cfs)
Facility Design
Flow,
(cfs)
IWC, ( %)`
001 0
3.1 100%
The IWC for this permit is 100 %, which represents a wastewater concentration of 100 %
effluent to 0% receiving stream.
Chronic WET Limit — This facility discharges both chlorine and ammonia, both of which can
cause toxicity at low concentrations. On this basis, the Division believes there is reasonable
potential for the discharge to interfere with attainment of applicable water quality classifications
or standards. Because of this condition, the chronic limit has been incorporated into the permit
and becomes effective immediately. The results of the testing are to be reported on Division
approved forms. The permittee will be required to conduct two types of statistical derivations on
the data, one looking for any statistically significant difference in toxicity between the control
and the effluent concentrations and the second identifying the IC25, should one exist. Both sets
of calculations will look at the full range of toxicity (lethality, growth and reproduction). If a
level of chronic toxicity occurs, such that there is a statistically significant difference in the
lethality (at the 95% confidence level) between the control and any effluent concentration less
than or equal to the In -stream Waste Concentration (IWC) and if the lethality IC25 < the IWC,
the permittee will be required to follow the automatic compliance schedule identified in Part
I.B.7. of the permit, if the observed toxicity is due to organism lethality. Only exceedance of
the limitation specified in Part I.B.6. will trigger the requirement for conducting the automatic
compliance schedule identified in Part I.B.7. of the permit. If the toxicity is due to differences in
the growth of the fathead minnows or the reproduction of the Ceriodaphnia, no immediate action
on the part of the permittee will be required. However, this incident, along with other WET data,
will be evaluated by the Division and may form the basis for reopening the permit and including
additional WET limits or other requirements.
Based on DMR data of last 5 years, the facility requested a testing relief for WET monitoring
under CWQCD Biomonitoring Guidance Document. After evaluating the data set, it was
concluded that annual monitoring instead of quarterly monitoring is warranted.
c. General Information — The permittee should read the WET testing section of Part I.B.6. of the
permit carefully. The permit outlines the test requirements and the required follow-up actions
the permittee must take to resolve a toxicity incident. The permittee should read, along with the
documents listed in Part I.B.7. of the permit (IF APPLICABLE), the Colorado Water Quality
Control Division Biomonitoring Guidance Document, dated July 1, 1993. This document
outlines the criteria used by the Division in such areas as granting relief from WET testing,
modifying test methods and changing test species. The permittee should be aware that some of
the conditions outlined above may be subject to change if the facility experiences a change in
discharge, as outlined in Part II.A.2. of the permit. Such changes shall be reported to the
Division immediately.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 13, Permit No. CO -0046663
6. Stormwater— In some cases stormwater from wastewater treatment facilities is required to be covered
by a Colorado Discharge Permit System (CDPS) permit or a No Exposure Certification in order to be
discharged to Waters of the State.
Division records indicate that the Town of Berthoud applied for and obtained coverage under a No
Exposure Certification for the Berthoud WWTF. The tracking number is NOX000283. Stormwater
permitting issues for this facility will be handled separately by the Division's Stormwater Unit.
7. Economic Reasonableness Evaluation — Section 25-8-503(8) of the revised (June 1985) Colorado
Water Quality Control Act required the Division to "determine whether or not any or all of the water
quality standard based effluent limitations are reasonably related to the economic, environmental,
public health and energy impacts to the public and affected persons, and are in furtherance of the
policies set forth in sections 25-8-102 and 25-8-104."
The Colorado Discharge Permit System Regulations, Regulation No. 61, further define this
requirement under 61.11 and state: "Where economic, environmental, public health and energy
impacts to the public and affected persons have been considered in the classifications and standards
setting process, permits written to meet the standards may be presumed to have taken into
consideration economic factors unless:
a. A new permit is issued where the discharge was not in existence at the time of the classification
and standards rulemaking, or
b. In the case of a continuing discharge, additional information or factors have emerged that were
not anticipated or considered at the time of the classification and standards rulemaking."
The evaluation for this permit shows that the Water Quality Control Commission, during their
proceedings to adopt the Classifications and Numeric Standards for South Platte River Basin,
Laramie River Basin, Republican River Basin, Smoky Hill River Basin, considered economic
reasonableness.
Furthermore, this is not a new discharger and no new information has been presented regarding the
classifications and standards. Therefore, the water quality standard -based effluent limitations of this
permit are determined to be reasonably related to the economic, environmental, public health and
energy impacts to the public and affected persons and are in furtherance of the policies set forth in
Sections 25-8-102 and 104. If the permittee disagrees with this finding, pursuant to 61.11(b)(ii) of
the Colorado Discharge Permit System Regulations, the permittee should submit all pertinent
information to the Division during the public notice period.
B. Monitoring
1. Effluent Monitoring — Effluent monitoring will be required as shown in the permit document. Refer
to the permit for locations of monitoring points. Monitoring requirements have been established in
accordance with the frequencies and sample types set forth in the Baseline Monitoring Frequency,
Sample Type, and Reduced Monitoring Frequency Policy for Industrial and Domestic Wastewater
Treatment Facilities. This policy includes the methods for reduced monitoring frequencies based
upon facility compliance as well as for considerations given in exchange for instream monitoring
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 14, Permit No. CO -0046663
programs initiated by the permittee. Table VI -2 shows the results of the reduced monitoring
frequency analysis for Outfall 001A, based upon compliance with the previous permit.
Based upon the reduced monitoring frequency analysis for Outfall 001A shown in Table VI -2, the
permittee is not eligible for reduced monitoring for pH, E.Co1i, BOD5, TSS, Cr+6, CN and Hg.
The quarterly monitoring frequency for mercury is imposed consistent with the Divisions' recent
initiative to include quarterly monitoring for mercury because of the changes in analytical procedure
that will allow total mercury to be quantified at much lower concentrations.
Outfall MON1 monitoring requirements are established consistent with Division procedures for
monthly monitoring to obtain data for use in future reasonable potential analyses.
Table
;.. ..
Parameter
Proposed
Permit Limit
Average of30-
Day(or,Daily
Max) Average
Conc.
Standard:'
- Deviation :
Yong Term
Characterization
(LTC)
Reduction
Potential
pH(eu) Minimum
men 6.5
6.9
7.7
0.32
0.32
6.26
8.34
None
p11 (su) Maximum
max 9.0
E. coli (#/100 ml)
126
NA
NA
NA
NA
TRC (mg/1)
0.011
0
0
0
3 Levels
NH3, Tot (mg/1)
2.8
0.12
0.17
0.46
3 Levels
BOD5, effluent (mg/I)
25
2.7
1.1
4.9
3 Levels
TSS, effluent (mg/1)
30
6.5
1.9
10.3
3 Levels
Cr+6, Dis (mg/1)
11
2.5
4.6
11.7
None
Cu, Dis (pg/1)
29
16
3.8
23.6
1 Level
CN, Free (pg/l)
5
5
9.3
23.6
None
Hg, Tot (pg/I)
0.01
0.044
0.088
0.22
None
Se, Dis (pg/1)
4.6
0.73
I
2.73
2 Levels
2. Pretreatment Program - The permittee is not required to maintain a formal pretreatment program.
However, conditions for industrial waste management conditions will be included in the permit.
C. Reporting
1. Discharge Monitoring Report — The Town of Berthoud must submit a Discharge Monitoring Report
(DMR) on a monthly basis to the Division. These reports should contain the required summarization
of the test results for all parameters and monitoring frequencies shown in Part I.B of the permit. See
the permit, Part 1.B, C and D for details on such submission.
2. Annual Biosolids Report — The permittee will be required to submit an annual Biosolids Report
which includes the results of all biosolids monitoring performed for the year and information on
management practices, land application sites, site restrictions and certifications. The Annual
Biosolids Report is due by February 19th of the following year. Refer to Part I, Section D.3 of the
permit.
3. Special Reports — Special reports are required in the event of an upset, bypass, or other
noncompliance. Please refer to Part ILA. of the permit for reporting requirements. As above,
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 15, Permit No. CO -0046663
submittal of these reports to the US Environmental Protection Agency Region VIII is no longer
required.
D. Additional Terms and Conditions
1. Signatory Requirements — Signatory requirements for reports and submittals are discussed in Part I,
Section D.1 of the permit.
2. Compliance Schedules — The following compliance schedules are included in the permit. See Part
I.A.8 of the permit for more information.
a. Cyanide and Mercury Compliance Schedule - Cyanide (WAD) daily maximum will be `Report'
until 08/31/2012 and starting 09/01/2012 it will be 5. This timeframe is selected to give facility
enough time for evaluation of treatment needed to meet the limit. Mercury (tot) 30 -day average will
be `Report' until 08/31/2012 and starting 09/01/2012 it will be 0.01. This timeframe is selected to
give facility enough time for evaluation of treatment needed to meet the limit.
All information and written reports required by the following compliance schedules should be
directed to the Permits Section for final review unless otherwise stated.
VII. REFERENCES
A. Colorado Department of Public Health and Environment, Water Quality Control Division Files.
B. "Design Criteria Considered in the Review of Wastewater Treatment Facilities", Policy 96-1, Colorado
Department of Public Health and Environment, Water Quality Control Commission, April 2007.
C. Basic Standards and Methodologies for Surface Water, Regulation No. 31, Colorado Department of
Public Health and Environment, Water Quality Control Commission, effective May 31, 2008.
D. Classifications and Numeric Standards for South Platte River Basin, Laramie River Basin, Republican
River Basin, Smoky Hill River Basin, Regulation No. 38, Colorado Department of Public Health and
Environment, Water Quality Control Commission, effective March 30, 2009.
E. Colorado Discharge Permit System Regulations, Regulation No. 61, Colorado Department of Public
Health and Environment, Water Quality Control Commission, effective March 30, 2009.
F. Regulations for Effluent Limitations, Regulation No. 62, Colorado Department of Public Health and
Environment, Water Quality Control Commission, effective March 30, 2008.
G. Pretreatment Regulations, Regulation No. 63, Colorado Department of Public Health and Environment,
Water Quality Control Commission, effective April 01, 2007.
H. Biosolids Regulation, Regulation No. 64, Colorado Department of Public Health and Environment,
Water Quality Control Commission, effective March 01, 2008.
I. Section 303(d) List of Water Quality Limited Segments Requiring TMDLs, Regulation No 93, Colorado
Department of Public Health and Environment, Water Quality Control Commission, effective April 30,
2008.
COLORADO DEPARTMENT OF HEALTH, Water Quality Control Division
Rationale - Page 16, Permit No. CO -0046663
J. Colorado's Monitoring and Evaluation List, Regulation No 94, Colorado Department of Public Health
and Environment, Water Quality Control Commission, effective April 30, 2008.
K. Antidegradation Significance Determination for New or Increased Water Quality Impacts, Procedural
Guidance, Colorado Department of Public Health and Environment, Water Quality Control Division,
effective December 2001.
L. Memorandum Re: First Update to (Antidegradation) Guidance Version 1.0, Colorado Department of
Public Health and Environment, Water Quality Control Division, effective April 23, 2002.
M. Determination of the Requirement to Include Water Quality Standards -Based Limits in CDPS Permits
Based on Reasonable Potential, Colorado Department of Public Health and Environment, Water Quality
Control Division, effective December2002.
N. The Colorado Mixing Zone Implementation Guidance, Colorado Department of Public Health and
Environment, Water Quality Control Division, effective April 2002.
O. Baseline Monitoring Frequency, Sample Type, and Reduced Monitoring Frequency Policy for Domestic
and Industrial Wastewater Treatment Facilities, Water Quality Control Division Policy WQP-20, May 1,
2007.
P. Implementing Narrative Standards in Discharge Permits for the Protection of Irrigated Crops, Water
Quality Control Division Policy WQP-24, March 10, 2008.
Q•
Procedural Regulations for Site Applications for Domestic Wastewater Treatment Works, Regulation
No. 22, Colorado Department of Public Health and Environment, Water Quality Control Commission,
effective June 30, 2004.
R. Regulation Controlling discharges to Storm Sewers, Regulation No. 65, Colorado Department of Public
Health and Environment, Water Quality Control Commission, effective May 30, 2008.
S. Water and Wastewater Facility Operator Certification Requirements, Regulation No. 100, Colorado
Department of Public Health and Environment, Water Quality Control Commission, effective
September 30, 2007.
Kenan Diker
May 19, 2009
VIII. PUBLIC NOTICE COMMENTS
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