HomeMy WebLinkAbout20013507 • • �`
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Epviropept,
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LARRY E. O'BRIAN 7985 VANCE DRIVE, SUITE 205A
FOUNDER ARVADA,COLORADO 80003
303-423-7297
FAX 303-423-7599
April 5, 2001
Clerk to the Board
Weld County Commissioners Office :7_r
915 10th Street, 3rd Floor
Greeley, Colorado 81003
Re: Application for a Mined
Land Reclamation Permit
Dear Sir/Madam:
We are delivering to you here with the final adequacy review
response packet for the S & H Mine to be operated by Platte Sand
& Gravel LLC . This copy of the adequacy review packet is deliv-
ered to you pursuant to 34-32 .5-112 (9 ) (a) , Colorado Revised
Statutes 1995, as amended.
This packet must be kept with the original book, for public
review until the permit has been approved by the Division. We
will contact you once it is and make arrangements to pickup this
copy.
Please acknowledge receipt of the copy of this packet by
signing in the appropriate space provided below and returning one
copy of this letter to the person delivering the book. This will
be submitted to the Division of Minerals and Geology to prove
this packet was delivered to your office.
Yours truly,
ENVIRONMENT, INC.
Stevan L. O'Brian
enclosure
RECEIVED THIS DAY OF , 2001, one
copy of an D.M.G. Adequacy review packet for above mine.
Weld County Clerk to the Board
By
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9706/-35)7
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•
Epvirouwent, Ipc.
LARRY E.O'BRIAN 7985 VANCE DRIVE,SUITE 206A
FOUNDER ARVADA, COLORADO 80003
303-423-7297
FAX 303-423-7599
April 4, 2001
Ms. Erica Crosby
Division of Minerals and Geology
1313 Sherman St. , #215
Denver, CO 80215
Dear Erica;
RE: Platte Sand & Gravel LLC
S&H Mine, Permit # M-2000-158
Platte Sand & Gravel LLC (PS&G) has asked me to respond to the
additional questions in your April 3, 2001 letter and the addi-
tional items Mr. Schreiner and Mr. Sorenson have asked. I will
respond in the order presented for each part of the letter.
1 . PS&G's attorney expects to have the waiver from the Mutual
Ditch Company later today or tomorrow. I will make sure you
get a copy as soon as it is available.
2 . The processing facilities would only be placed in the areas
shown as mining ,areas on Map Exhibit C-1 - Mining Plan Map.
Platte Sand & Gravel LLC understands the requirement of a
revision if the processing plant were moved to a "not dis-
turbed" area.
The original response was due to a misunderstanding on what
you needed. I concur that if, there are permanent plant
foundations etc. in the plant site that they would have to be
in the bond calculation. After discussing this with PS&G it
was determined that only portable plants would be on the site
until yearly volumes reach a point where permanent facilities
need to be built. These plants can be moved readily and no
permanent foundations would be built until a bond reevaluation
was complete.
The three plants involved are capable of being moved using
semis' and what usually amounts to 3 loads per plant. For a
portable asphalt plant this consists of: The plant, the bulk
storage tank, and supporting facilities . For the portable
•ENVIRONMENT, INC. • PAGE 2
APRIL 4, 2001
concrete plant they are very much the same; the plant, con-
crete silo and supporting facilities. The processing plant
again being portable, would have a screen deck, a crusher, and
conveyors that would use a total of 4 trucks . The plants and
material storage units all have axles so they can be towed.
The support facilities and conveyor would have to be placed on
trailers . There would be no footings, floors or permanent
slabs until the facility becomes fixed units .
The processing plant area will not discharge any thing that
would affect the surface or ground water quality except dirty
water. This water will be directed to the silt pond and
contained on the mining area. No special protection is
necessary for the processing plant. Once the exact location
for the asphalt and concrete plants is know, the area under
each site will be excavated to create a shallow depression. A
double layer of 6-mil vapor barrier will be used as a liner in
each depression. Then 4 inches of clean sand will be laid
over the barrier and roadbase material will cap the site. A
small containment berm will be placed around each plant site
to keep anything from leaving that particular site. The size
of the berm will be engineered to contain the amount of liquid
products stored in each plant site area. There will be ade-
quate sand to absorb spills that may occur around each plant
site. Any contaminated material will be disposed of properly
and current BMP's will be used at all times for these opera-
tions.
3 . The only improvements to existing roads that would be used as
internal haul routes would be to grade and gravel them. Good
gravel roads are compatible with the intended final reclama-
tion use of recreation and wildlife habitat. Our primary haul
route is the new road show on the Mining Plan Map. The south-
ern 2, 600 feet of the new road would have to be down sized if
your assessment were valid, but since this is an extension of
Weld County Road 23 it will be the best access into the site
when reclamation is complete. The landowners do not want it
narrowed or downsized and I have attached a notarized letter
from Krystal Hoffschneider to that effect. Therefore, no
additional work on the roads would be necessary if the Divi-
sion had to reclaim the site. This section of the main haul
road was inadvertently left off the Reclamation Plan Map. If
you will make your copies available, I will add this road to
them.
The oil companies have not specified how deep the oil lines
are at this time. They have admitted that no "as built" plans
exist for the lines, so it will be necessary to located each
line prior to mining in an area. This will also be necessary
along the haul route from Sharkeys' Lake to the south side of
Highland Lake. I assume they are below the normal frost level
which would place them 24 to 36 inches deep. The agreements
with the pipeline companies will address this issue and PS&G
ENVIRONMENT, INC. • . PAGE 3
APRIL 4, 2007
will do whatever is necessary to satisfy them. PS&G will
commit to not crossing buried gaslines or using roads with
gaslines under them as haul routes until a copy of the signed
working agreements are submitted to the Division. In leu of
the working agreements PS&G may opt to submit crossing and
road designs showing how the gaslines will be protected for
approval. Nothing in this proposal prevents the landowners,
or oil companies from using or improving roads for their use
if needed.
4 . I respectfully agree to disagree. However, PS&G will apply to
the Division if lining ever becomes an option.
The inclusion of the term "inert material" in the permit was
to protect the operator from enforcement action in the future
if any inert material were ever delivered to the site. The
plan does not include backfilling slopes with inert material
at this time and PS&G understands that a permit revision may
be necessary if that change is proposed in the future.
5 . Thanks for point this out. To restate the proposed plan only
1 acres will be dewater in each lake area to facilitate the
dredges ' placement. This is consistent with the Leonard Rice
study. PS&G understands any changes to the approved
dewatering plan would have to be submitted as a revision.
6 . The only inert material that would be used in the pit slopes
under the proposed plan would be concrete in sizes larger than
a basketball. An exact explanation is shown in the last
paragraph of page 12 in the application. This material would
be placed as bank armoring at the water line or as fish habi-
tat below the water line. On any material placed above the
water line the courser material would be in the lower layers
and finer material from basketball size to finer base material
would be placed in the next layer. The inert material would
then be covered with a minimum of 12 inches of growth medium.
The definition of inert material is very specific as to what
it can be. PS&G does not plan to make this site an inert
material depository, large scale recycling facility or land-
fill and plans to accept only material from their operations.
Each load will be inspected at the scale house as it comes
into the mine area and if it does not meet the definition on
our notarized affidavit it will be rejected and not allowed on
the site. If the load passes the scale house inspection, it
will be inspected again after it is dumped and prior to using
it for reclamation. Any material that does not meet the
definition of "inert material" will be segregated and removed
to an acceptable offsite depository.
Placement under wet mining conditions is fairly easy, one
simply dumps it along the lake and it is dozed into the lake.
It will settle to the bottom. The dredge would then be used
to pump finer material over it until the prescribed slopes are
•
ENVIRONMENT, INC. • PAGE 4
APRIL 4, 2007
reached. Remember PS&G plans to create the slopes as mining
progresses to keep the amount of baokfilling neeessary to a
minimum. Only the actual working face would need sloping as
explained in Exhibit S so the inert material would be placed
before the dredge shaped the slope. In the case of bank
armoring the material would be placed after sloping is com-
plete. Since dewatering of large areas is not allowed at this
time it would not be practical to build slopes with the inert
material.
7 . I respectfully disagree with your statement that the soils
report indicates there is 12" of topsoil on the site. The
information presented by Mr. Norman Wells in his letter did
not name a specific topsoil depth for the mine site. The
supporting data sheets he provided are general soil descrip-
tions for the entire county and are not site specific . The
soils depth, from site specific observations, was stated on
page 12 paragraph 4 of the application and in part states ". .
. average salvageable soil depth is 4 to 6 inches . . . " .
This was a stated average intended to indicate there where
areas with more and less topsoil. For example, most of the
circle area in Sharkey's Lake, the Bluffs Lake and the High-
lands Lake areas contain little or no topsoil material . The
application then noted: "Never-the-less, what soils can be
salvaged will be stockpiled in perimeter areas and used in
resoiling when final grading is completed. There appears to
be more than adequate soils to meet the demand. " As noted in
response #6 above, any resoiling to be done on areas where
inert material is used as fill will have a minimum of 12 of
topsoil placed over a base layer of finer materials . On
slopes that do not contain inert material, PS&G will place an
average of 6 inches as described in the application.
8 . All ditches that are to be mined thru and are internal to the
site and do not serve adjacent property owners .
9 . I understand this statement and refer you to the discussion in
my letter of March 30, 2001 addressing this point.
10 . Attached is a large scale version of this map for your file.
There was a mistake in the legend that appeared to show the
cross hatched area as you describe. When the map was prepared
the background information was toned down so they did not
clash with the wetland delineation being shown on the map.
The legend was toned down inadvertently when printed and this
is corrected on the attached map. I have enclosed, copies of
two letters from Mr. Tim Carry of the US Army Corps of Engi-
neers clarifying 404 permitting requirement in the first 15 to
20 year of the mine life and addressing the new road location,
for the file .
The key statement to your request for placing 404 permitting
requirements in the permit is "If the reclamation plan re-
ENVIRONMENT, INC. • • PAGE 5
APRIL 4, 2001
quires replacement of wetlands. The proposed reclama-
tion plan does not incorporate replacing wetlands at this time
since there are no wetland areas in the places where mining
will take place over the first 20 plus years. Replacement
wetlands, under 404 rules, are not a reclamation project, but
are rather a mitigation and reconstruction requirement of a
404 permit. PS&G will follow the jurisdictional agency's rules
when and if they remove wetland areas . M.L.R.B. Rules and
Regulations do not cover wetland removal methods and mitiga-
tion nor can the Division enforce another agency' s rules. As
I understand it, the Division can only advise an operator that
they have to comply with another agency's rules and if they
fail to comply, then the Division can take action against them
for not complying. But in this case, if PS&G is in compliance
with 404 requirements, then the M.L.R.B. has no jurisdiction
to require PS&G to include wetland mitigation projects in the
reclamation plan.
11 . Responses to their comments follow this text.
12 . So noted. I will review your number when we receive them.
Memo From Tom Schreiner:
1 . The excavation limits are shown as cross hatched areas on the
revised copy of the Mining Plan Map. Due to the scale neces-
sary for the map any dimensions would be so small as to be
unreadable. The setbacks can be scaled from these maps since
they vary and the written text supports or qualifies what the
map shows . Placing product, topsoil and overburden (none on
this site) locations on this map would at best be a guess and
could only be done at the time shown on the map. PS&G has
committed to stockpiling topsoil around the perimeter of the
mined area within 500 feet of where it is needed. In most
cases PS&G will be stripping and resoiling at the same time to
avoid moving material twice. In this case, only the topsoil
pile adjacent to the Plant site would exist. I request that
this requirement be waved since it has been adequately ad-
dressed in the application and this text.
8. Platte Sand & Gravel LLC is requesting that the recommendation
to minimize impacts during dewatering from the Leonard Rice
Consultants letter be incorporated in the mining and reclama-
tion plans. PS&G will commit to following the recommendations
as the mine develops. Specifically, mining in each dewatering
area will begin in early summer so that aquifer dewatering is
complete prior to the next irrigation season. Mining in each
lake area will be done as far from off site wells as possible
and as close to the river as practical for the lake area
development. PS&G understands the requirement to submit an
additional hydrologic assessment if changes to the dewater
plan are necessary. They understand that the Division will
determine the permit modification method upon reviewing the
•
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ENVIRONMENT, INC. PAGE 6
APRIL 4, 2001
submittal and advises PS&G as to whether the revision should
be an amendment or a technical revision.
9 . I am still waiting for this information from Kris Pickett of
Pickett Engineering and will respond to this request under
separate cover as soon as I have the information.
12 . I disagree with this statement. As noted in my response to 10
above, the proposed reclamation plan does not incorporate
replacing wetlands at this time since any wetlands that occur
around the lake areas will be created voluntarily. Replacing
wetlands under 404 rules are not reclamation projects, but is
rather a mitigation and reconstruction requirement in a 404
permit. PS&G will follow the jurisdictional agency's rules
when and if they remove wetland areas . M.L.R.B. Rules and
Regulations do not cover wetland removal methods and mitiga-
tion nor can the Division enforce another agency's rules . As
I understand it, the Division can only advise an operator that
they have to comply with another agency's rules and if they
fail to comply, then the Division can take action against them
for not complying. But in this case, if PS&G is in compliance
with 404 requirements, then the M.L.R.B. has no jurisdiction
to require PS&G to include wetland mitigation projects in the
reclamation plan.
Memo from Alan Sorenson
I just received Alans' items and will respond to his memo under
separate cover when I address Tom's concerns for item #9 .
I hope these responses address the items to your satisfaction.
A copy of this response will be placed with the Weld County Clerk
of the Board as required. If you have any questions please call
me.
Sincerely,
Environment, Inc
Stevan L. O'Brian
President
cc Weld County Clerk
Platte Sand & Gravel LLC
file
Epviroet,•
•
I c.
LARRY E.O'BRIAN 7985 VANCE DRIVE, SUITE 205A
FOUNDER ARVADA, COLORADO 80003
303-423-7297
FAX 303-423-7599
April 5, 2001
Ms. Erica Crosby
Division of Minerals and Geology
1313 Sherman St. , #215
Denver, CO 8O215
Dear Erica;
RE: Platte Sand & Gravel LLC
S&H Mine, Permit # M-2OOO-158
Platte Sand & Gravel LLC (PS&G) has asked me to respond to
the additional items Mr. Schreiner and Mr. Sorenson have asked
answers for. I will respond in the order presented for each part
of their memos and the additional information we discussed today.
Memo from Tom Schreiner
9 . Today (4/5/01 ) my discussion with Mr. Schreiner centered on
what type of information he needed and the reasoning behind
the request. PS&G is making the following commitment to
give their engineers time to do a thorough analysis and
develop a plan that would be acceptable to the Division.
PS&G will commit to not mining in the floodplain until a
floodplain analysis and mitigation plan is developed and
submitted to the Division for review and approval. This
analysis may be complete prior to the Mined Land Reclamation
Board hearing on April 25-26 . I will submit this as soon as
it is available.
Memo from Alan Sorenson
Response 25 :
PS&G will commit to not constructing lateral berms or leave
one within 400 feet of the top of the riverbank unless the
Division has approved a design for protection on the lateral
berms . The operator will file a lateral berm protection
plan with the Division prior to constructing a berm within
400 feet of the river if it becomes necessary.
Response 26 :
PS&G will commit to not mining within 4OO feet of the top of
the riverbank until an armoring and bank stabilization
design has been submitted to the Division and approved. The
•ENVIRONMKNT, INC. - • PAGE Z
APRIL 5, 200 7
operator will file a bank stabilization plan with the Divi-
eion prior to mining within 400 feet of the river.
other:
Tom Schreiner and I discussed the 404 permit issue, and he
explained the Divisions concerns and reasoning on why the
staff made this request. We arrived at a reasonable compro-
mise so: PS&G will commit to submitting copies of any 404
permit wetland mitigation applications made to the US Army
Crops of Engineers, to the Division, so the Division can
determine what course of action will be needed regarding the
reclamation permit.
Attached is a copy of the Weld County Clerks placement
receipt for our March 30, 2001 adequacy response packet.
Clarification for items #6 on 4/4/01 response
The size of inert material that will be delivered to the
site is classified as minus 3 foot.. As part of the inspec-
tion plan, each load will be documented at the scale house
to keep track of the type and quantity of inert material
accepted and how is . was disposed. These records will be
maintained in our corporate offices .
I hope these responses address the items to your satisfac-
tion. A copy of this response will, be placed with the Weld
County Clerk of the Board as required. If you have any questions
please call me.
Sincerely,
Environment, Inc
Stevan L. O'Brian
President
cc Weld County Clerk
Platte Sand & Gravel LLC
file
•
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APP. 2.2001 1:28F'M DPa. 11IIIERRLS&GE0L0GY 8".371 P. 1'5
STATE OF COLORADO
DIVISION OF MINERALS AND GEOID
of Department of Natural ResoUsopges
1313 Sherman Si.,Room 215 post-It Fax Note 7071 Pet• appea► -
P•nver,Colored0 00203 '1 m, 1p,,, Prom P I V 1 b 1 O N o F'
Phone:(303)866.3567 0 �71'1b.V� tQ� MINERALS
FAX:(303)832-8106 1 Co./De IiJ( _ .t/Pt Co. Dyt/1 &
Phone o II PIMna N 2tov^.k , qqq GEOLOGY
yy�yFax
q�,� {�I� RECLAMATION
April3, 2001 e,IN ^lia3- 67:71 FaxH 'bIi'J-e63; -�l`-1 MINING-SAFETY
Gill Owens
Rocky Hoffschneider Governor
Platte Sand& Gravel LLC Crob E.Walther
P.U. BOX 180 Executive Director
Littleton,CO 80106 Michael
M s on Dire for
RE; Platte Sand& Gravel LLC,File No.M-2000-158
S&H Mine 112 New Permit Application
Adequacy Review#2
Dear Mr.Hoffschneider,
The Division received your adequacy response to the Division's February 22, 2001 letter regarding the new
permit application for the S & H Mine,File No, M-2000-158. The Division has a number of remaining items that
need to be addressed prior to approval of the application.
1. The applicant provided copies of the return receipt cards for adjoining owner nd easement holders of record.
Western Mutual Ditch was identified as an adjacent landowner on Map Exhi it C, but a return receipt card
was not submitted. Please submit the return receipt card for Western Mutual Ditch. If the applicant failed to
notify the ditch company,they must do so and allow a 20-day comment period. If Western Mutual Ditch opts
to waive their right to the 20-day comment period, a letter stating this fact would be acceptable. Please be
aware that the letter and signature must be notarized.
2. The applicant contends that moving the processing facilities throughout the permit area does not need to be
addressed as a revision to the permit. The Division agrees with this statement so long as the processing
facility is moved within the designated affected land. If the processing facilities are moved into lands that are
designated as"not disturbed,"then a revision to the permit will be necessary.
The applicant also states that the cost to remove the facilities do not need to placed in the bond calculation
since they will be allowed under the county permit and would be removed as an asset if mining ended
prematurely. The Division is required to estimate a cost to reclaim the site to the proposed postmining laud
use of recreation and wildlife habitat. Such facilities are to be removed to achieve the reclamation plan. The
definition of affected land includes "...structures, facilities, equipment, machines, tools or other materials or
property which result from or are used in such operations are situated." Regardless of other permits issued by
the County, State or Federal Agencies, it is the Division's jurisdiction to hold a reclamation bond in the
amount necessary to reclaim the site in the event of permit revocation and bond forfeiture (C.R.S. 34-32.5-
117).
In order for the Division to calculate the cost to remove such facilities, the application will need to provide
additional information on each of the structures;
• Length,width and height
• Composition of the facility(concrete,steel, wood,etc...)
•
cIPR. 3.2001 1:29Pt1 DIV IIItIERRLS&GEOLOGY H0.371 P.2!5
• Dimension and composition of any and all floors and footings
In addition, the operator will need to specify a plan to ensure surface water and groundwater will not be
impacted from operations at the Plant Site.
3. The applicant states that on site roads will not he improved unless used as a haul routes, and most of the
roads will remain when mining ends to allow access to oil well facilities on the site. Please specify the
increase in width of the existing roads. In addition, the improved roads and new roads will need to he
downsized to achieve the purpose of the postmining land use of recreation and wildlife habitat, The applicant
will need to specify the width of the improved road, the width of the road proposed for reclamation, and the
overall length of the roads to be improved and reclaimed. This will be taken into account in the reclamation
cost estimate.
Please also specify how roads will be improved to ensure that the oil production lines will be protected from
use of haul truck and truck traffic. Please specify the depth of oil line below the ground surface and the
thickness of road base material to be placed on the roads.
4. The applicant states that if PS&G chooses to seal one of the lakes, fill it with water they purchase/own and
use it for recreation it does not change the final reclamation plan. Lakes that are lined either by shiny wall or
compacted clay liners for the purpose of storing water does change the end land use to developed water
resources. Such change would require an amendment to the permit.
Please also be aware that backfilling with inert material and lack of compacted pit slopes may require a
greater off set distance for the location of the slurrywall or the need of additional compaction of the backfilled
pit. All of these issues will need to be addressed through the amendment process.
5. The applicant states that the area of dewatering will be limited to 5-acres or less in each lake area as far from
the permit boundary a possible. The report prepared by LEONARD RICE CONSULTING WATER
ENGINEERS, INC. evaluates the potential impacts to nearby wells in terms of lowered water levels resulting
from the dewatering of 1-acre pit sites for dredge construction. The operator clarified this discrepancy by
letter on March 30, 2001.
In addition, the applicant states that LEONARD RICE CONSULTING WATER ENGINEERS, INC. is also
working on a long term plan that may involve building and/or installing a water recharge ditch/lake up
gradient from the dewatered area that would act as a recharge barrier and allow dewatering on larger areas in
the mine. This report will need to be submitted as a revision to the permit. In fact, any dewatering area larger
than one acre in size will need to be approved by the Division in the form of a revision to the permit.
6. The applicant provided additional information regarding inert materials that may be hauled into the site and
used to reclaim the pit slopes. The Division will need some additional information on the importation of inert
fill;
• Please specify the size and gradation of the material to be placed in the pit.
• The cover material and depth to be placed over the inert material (6" replacement depth as stated in
application is not acceptable).
• On site controls,monitoring and recording methods to Insure that the material is indeed inert material.
In addition, the placement of the inert material using heavy equipment does not seem feasible if the area is to
be wet mined. Please specify how the inert material will be placed as backfilled material under the current
mining conditions to achieve the reclaimed slopes of 2h:Iv and 3h:lv 10 feet below and 5 feet above the
expected water line.
2
•
•
•
APR. 3.2001 1:30Ft1 DIV/MIAERALSgGEOLOGY 110.371 P. 3
7. The applicant rejects the recommendations of the NRCS regarding seeding and mulching. The Divisior is
aware that limited topsoil exists on the site,but the soil study included in the application indicates that 12" of
material can be salvaged from the permit area and used on the reclaimed slopes. This becomes relevant where
slopes are backfilled with inert material containing a mixture of dirt, rocks, concrete and asphalt. A more
suitable rooting depth than 6" should be applied. Please commit to a 12" topsoil replacement depth on
backfilled and graded slopes above the expected groundwater level.
8. Please clarify to the Division that all ditches that are to be mined through are internal to the property and do
not serve an adjacent property owner or infringe on others water rights.
9. The applicant has removed "wildlife habitat" as one of the postmining land used for the site, As per our
conversation on March 28, 2001, if the applicant chooses to do this the landowners will need to be renotitied
and the notice will need to be republished in the paper. All time frames will begin anew. Correspondence
dated March 30, 2001 left"wildlife habitat"as a postmining land use.
10. The applicant provided at Wetlands Map in the submittal dated March 26, 2001. It is difficult to determine
the wetland areas as noted on the legend. According to the legend, Sharkey's Lake and portions of the South
Platte River are deemed wetlands. The legend does not denote the crosshatched areas of the map that extend
along the majority of the South Platte River. Please clarify.
The applicant states that the Division has no jurisdiction over wetlands, and states that it is not practical to
incorporate a 404 permit requirements in the Reclamation Plan. As stated above, it is the Division's
jurisdiction to ensure that the site is bonded to achieve the final reclamation of the site. If the reclamation
plan requires replacement of wetlands,as dictated by the U.S. Army Corps of Engineers, then it needs to he
included in the cost estimate. In order to estimate a cost for wetland reestablishment,the wetland mitigation
plan must be included in the permit.
11. Enclosed, please find additional questions and comments from Tom Schreiner and Allen Sorenson with the
Division. Please respond to the questions accordingly.
12. The Division is in the process of finalizing the reclamation cost estimate. Once the estimate is complete, the
applicant will be notified under separate cover.
The Division's decision due date was extended by the applicant to April 6, 2001, Please respond to these
concerns prior to this date.
If you have any questions,please do not hesitate to call me at 303-866-4943.
Sincere y,
caaro),
Erica Crosby
Environmental Protection Specialist
Enclosure(s)
cc: Carl Mount;DMO
Stevan O'Brian; Environment,Inc. w/enclosure
Marty Block;Xcel Energy w/enclosure
Michael Decker w/enclosure
3
•
•
APR. 3.2001 1:31PH DIV/IiII IEPALC3 GE0Lor;y
H0.371 F.4
STATE OF COLORADO
DIVISION or MINERALS AND GEOLOGY --
Depanment of Natural Resources
1313 Sherman St.,Room 215
Denver,Colorado 80203 n 1 v l S l O r
Phone:(303)866-3567
FAX:(3031032-8106 MINER
GEOLO
Date : April 3, 2001 RECLAMA1
t11h11NG•sA
To : Erica Crosby, Carl Mount Bill Omni'
� Governor
From : Torn Schreiner '//�" Greg E.l‘alrhr.r
EAeauli Director
Michael e.tong
Divicinn Dirrrinr
RE: S & H Mine 112 Application, Platte Sand & Gravel LLC, File No, M-2000-I58
2nd Hydrologic Adequacy Review
I have reviewed the objector's March 9, 2001 comments and the applicant's March 27, 2001
adequacy review comments. The items listed below are outstanding hydrologic concerns that
will require either clarification or additional information from the applicant. I recommend that
these concerns be resolved to the satisfaction of the Division prior to a recommendation of
approval,
6.4.3 EXHIBIT C -Pre-Minim & Minima Plan Map(s) o[Affected Lands
1. In conformance with Rule 6.4.3(d), the Division requests that the mine plan map be revised to
show the limits of excavation (if other than the affected.land boundary) and the proposed
setbacks from the South Platte River and the Western Mutual Ditch. In addition, the
approximate location and orientation of any product, overburden, or topsoil stockpiles (if located
in areas away from the processing area) should also be noted. Please address, .
6.4.7 EXHIBIT G - Water Information
S. The applicant has provided a hydrologic analysis (prepared by Leonard Rice Consulting Water
Engineers, Inc.) including a predicted cone of depression for 1-acre areas to be dewatered and dry
mined during the life of the operation. The hydrologic assessment indicates that there will be
minimal impacts to offsite wells located within 600 feet of the affected land. The hydrologic
assessment also provides specific reconunendations for the applicant which will help ensure
minimization of possible impacts to other ground water users. The Division agrees with the
dewatering results predicted by LRCWE and the recommendations for minimization of possible
impacts, Accordingly, the Division will be in favor of approval of this application provided the
applicant will commit to or incorporate the parameters of the LRCWE analysis into their mining
• and reclamation plan. Also, the Division requests that the applicant clarify whether they will
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• S
APR. 3.2001 1 c 31PI1 ['I'V.'I tItIEPnLS¢GEnL n HO.?-1 P
incorporate the recommendations for minimizing impacts during dewatering into their mining
and reclamation plan. Finally, in the event that the applicant wishes to dewater areas larger than
1-acre and/or deeper than 25 feet below the ground surface, the Division will require a
modification to the permit which includes a hydrologic assessment of the potential impacts and
mitigation measures to be employed, as necessary. The Division will evaluate (at the time of
submittal) whether the permit modification should be processed as a technical revision or a
permit amendment.
9. Due to the close proximity of the S & H Mine to the South Platte River and the length of time
projected for mining and reclamation (100+years), it is likely that disturbed areas within the
permit area will experience a significant flood event several or more times throughout the life of
mine. Accordingly, the Division requests that the applicant clarify the flood elevation and peak
flow velocity expected a "worst case" flooding event and specific measures that the operator will
implement to minimize the potential for any offsite impacts. Mitigation measures might include
mining dry pit slopes at a maximum of 1:1, installation of flood control spillways within the
reclaimed lakes, installation of drainage pipes within the internal berms separating pits and/or
reclaimed lakes, armoring internal berms separating pits and/or reclaimed lakes, or armoring
reclaimed pit slopes in close proximity to the South Platte River with erosion control riprap.
Please address.
6.4.13 EXHIBIT M • Other Permits & Licenses
12. In the event that a 404 or other permit is required by the Army Corps of Engineers (either
now or in the future), the Division requests that the applicant review the terms and conditions of
the permit. If such terms and conditions require wetlands mitigation, wetlands construction, or
wetlands enhancement within the permit boundary for M-2000-158, then the plans and costs for
such mitigation, construction, or enhancement will need to be incorporated into the reclamation
plan. This may be accomplished via a technical revision to the mining and reclamation permit,
Please comment,
'� � -
oat-IN Fax Note 7671 Date Ito
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To: Erica Crosby
From:Allen Sorenson !�
CC: Carl Mount, Tom Schreiner
Date: 04/04/01
Re: Adequacy Responses, S&H Mine, Platte Valley Sand & Gravel, File No, M-2000-158
I have reviewed responses numbered 25-27 and 38 in the Applicant's letter and
attachments dated March 26, 2001. The Applicant's response number 38 satisfies the
Division's concern with mining setbacks to structures including gas lines and wells.
Response number 27, relating to the alignment of temporary overburden and topsoil
stockpiles, is also satisfactory. Additional clarification or commitments related to responses
numbered 25 and 26 will be required for the Division to recommend approval of the
application.
Response no. 25: The Division was not concerned that the operation of the pit will increase
floodwater surface elevations in the floodway and floodplain, and agrees with the Applicant's
analysis that potential floodwater elevations will actually decrease as the pit is mined out.
The Division's concern is with the potential for the high velocity flows of the main stem of the
river to he diverted through the pits because of floodwaters down cutting the land separating
the pits from the river and land separating the pits from each other. Land that separates the
pits from the river, whether that land is built up through placement of fill or is simply native, in
situ ground that is left intact, is referred to as a "riverside berm." Riverside berms are further
discussed below. Ground that is left intact or built up using fill between pits, and generally
athwart of the anticipated direction of potential flood flows, are called "lateral berms." The
Applicant states that there will be no placement of fill in the construction of lateral berms,
However, the berms comprised of native material left in place between pits are similarly
subject to differential head and down cuffing during a flood. This can lead to a number of
potential problems including sequential, progressive failure of lateral berms in a downstream
direction, temporary or permanent diversion of the main stem through down cut channels in
failed riverside and lateral berms and through the pits so linked, and damage to the pipelines
that are carried in the berms. If any lateral berms am to be left within 400 feet of the top of
the bank of the river, the Applicant must install structures to equalize hydraulic head on
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either side of the berms during a flood, or provide a demonstration that anticipated
differential head will not cause down cutting. The structures to be installed may be designed
based on site specific conditions determined through the floodplain analysis currently being
conducted, or may be Installed In accordance with the general designs and specifications
included in the "Technical Review Guidelines for Gravel Mining Activities," Urban Drainage
and Flood Control District, December 1987. (The Division recognizes that the proposed
S&H Pit is outside of the District, but that does not invalidate the technical aspects of the
guidance). In either case, a stipulation or commitment should be included in the permit that
lateral berms will not be constructed or left in the mined or reclaimed area unless they are at
least 400 feet from the top of the riverbank or unless the Division has approved a design for
stabilization and collected appropriate bond to assure that stabilization measures will be
completed.
Response no. 26: The Division supports the Applicant's commitment to maintain a 400 foot
mining setback from the top of the riverbank in all areas were armoring of the riverside berm
is not in place or will not be installed. The Division further concurs with the Applicant that
mining within 250 feet of the riverbank can proceed with appropriate armoring of the
riverside bank of the berm, and within 150 feet where appropriate armoring of both the
riverside and pitside banks of the berm is installed. However, the application remains
ambiguous as to the nature of the armoring to be Installed. A stipulation or commitment
should be included in the permit that riverside berms will not be constructed or left in the
mined or reclaimed area unless they are at least 400 feet wide (from the top of the riverbank
to the top of the pit bank) or unless the Division hes approved a design tor armoring and
collected appropriate bond to assure that stabilization measures will be completed. Again,
the Urban Drainage and Flood Control guidance includes general designs and specifications
for riverside berm stabilization that would be acceptable to the Division.
m.'nin\acs\s&H MInv2.doc
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File contains
oversized map
See Original File
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