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Home My WebLink About20050077 Northern Colorado Ato Geotech June 11, 2004 2956 29th Street, Unit 21 Greeley, Colorado 80631 Phone: (970) 506-9244 Fax: (970)506-9242 Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Clayton Harrison Re: Mineral and Aggregate Report Highway 37 and Weld County Road 601/2 Gill, Colorado Northern Colorado Geotech Project No. 132-03 Northern Colorado Geotech performed test borings at the above referenced property in August 2003 in anticipation of a small residential development. The soils encountered in the test borings consisted of silty sand, silty clayey sand and sandy lean clay. Based on previous experience near the site, claystone and siltstone bedrock can be expected within 10 to 20 feet below existing site grades. The proposed development is located within the Great Plains physiographic province. The Colorado Piedmont is located near the western border of the Great Plains province and was formed during Late Tertiary and Early Quaternary time (approximately 2,000,000 years ago). The Colorado Piedmont is a broad, erosional trench which separates the Southern Rocky Mountains from the High Plains. Structurally, the site lies near the axis of the Denver Basin. During the mountain building of the Laramide Orogeny (approximately 70,000,000 years ago), intense tectonic activity occurred, causing the uplifting of the Front Range and associated downwarping of the Denver Basin to the east. Due to the erosional action of wind and streams, relatively flat uplands and broad valleys characterize the present-day topography of the Colorado Piedmont in this region. The site is underlain by the Cretaceous Laramie Formation. The Laramie is generally comprised of sandstone, siltstone and claystone units. The Laramie also contains significant coal seams in southern Weld County and Boulder County. Based on our borings and a literature review, it is our opinion that there are no economic sand or gravel aggregates at the site. Due to the type of bedrock formation(s) which underlie the site, it is our opinion that no economic quantities of quarry rock are available at the site. Based on the review of maps in the area, we are unaware of coal mines in the immediate vicinity of the site. Therefore, it is our opinion that there are no economic quantities of minerals or aggregate at the subject site. 2005-0077 r-. n Mineral and Aggregate Report Highway 37 and Weld County Road 601/2 Northern Colorado Geotech Project No. 132-03 If you have any questions concerning this report or any of our consulting services, please do not hesitate to contact us at (970) 506-9244. Sincerely, NORTHERN COLORADO GEOTECH Prepared by: tc Pc Doug Leafgr92, P President Copies to: Addressee (2) b 3-033// 5.D (17//2-44-7.4 'Dos, ,k.e / AJO/d._ Sd SO/c-"5/c-\G PRELIMINARY SOIL PERCOLATION REPORT PROPOSED RESIDENTIAL DEVELOPMENT HIGHWAY 37 AND WELD COUNTY ROAD 60'/2 GILL, COLORADO NORTHERN COLORADO GEOTECH PROJECT NO. 132-03 AUGUST 8, 2003 Prepared for: Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Clayton Harrison Northern Colorado Geotech 2956 29th Street, Unit 21 Greeley, Colorado 80631 Phone: (970)506-9244 Fax: (970) 506-9242 r" I7 i ,/1 Northern Colorado Geotech September 22, 2003 2956 29th Street, unit 21 Greeley, Colorado 80631 Phone: (970)506-9244 Fax: (970)506-9242 Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Clayton Harrison Re: Addendum to Preliminary Soil Percolation Report Highway 37 and Weld County Road 60% Gill, Colorado Northern Colorado Geotech Project No. 132-03 Northern Colorado Geotech has been asked to comment on the anticipated foundation and construction of single-family residences at the above referenced site. Northern Colorado Geotech performed test borings and preliminary percolation tests at the above referenced property in August 2003. The subsurface soils at the site consisted of silty sand, silty clayey sand and sandy lean clay. The results of the preliminary field exploration indicate that the soils have low load bearing capabilities. Groundwater at the site was encountered at depths of 4 to 6%feet. Based on the site anticipated development, it is our opinion that residences may be constructed using conventional type spread footing foundations. Footings may be preliminarily designed for maximum bearing capacities of 750 to 1,500 psf. Generally foundations should be placed a minimum of 3 feet above the groundwater. This may preclude the construction of basements in some areas unless site grades are raised or groundwater levels are lowered. Each building location should have a site specific soils evaluation performed to determine load bearing, groundwater levels and soil percolation rates prior to the start of construction. If you have any questions concerning this addendum or any of our consulting services, please do not hesitate to contact us. Sincerely, NORTHERN COLORADO GEOTECH Prepare by: Doug Lea g en P. `\..,e-c,1 ,7- " President i Reviewed by: ,_----7 Gary G. Weeks, P.E. Vice President Copies to: Addressee (3) Northern Colorado Geotech August 8, 2003 2956 29th Street, Unit 21 Greeley, Colorado 80631 Phone: (970)506-9244 Fax: (970)506-9242 Pickett Engineering 808 8th Street Greeley, Colorado 80631 Attn: Mr. Clayton Harrison Re: Preliminary Soil Percolation Report Highway 37 and Weld County Road 60% Gill, Colorado Northern Colorado Geotech Project No. 132-03 Northern Colorado Geotech has completed preliminary soil percolation testing for a potential "estate- style" residential development at the project site. The subsurface soils at the site consisted of silty sand, silty clayey sand and sandy lean clay. The results of our field exploration indicate that the soils have fair percolation rates. Groundwater at the site was encountered at depths of 4 to 6%feet. Based on the anticipated development and the results of our preliminary exploration, it is our opinion that septic systems are feasible at the site. Due to the relatively shallow groundwater encountered at the site, it is our opinion that septic systems in portions of the site may require mounding to provide adequate clearance above the groundwater. Prior to the start of residential construction, complete soil and percolation tests should be performed to adequately design foundations and septic systems for each residential location. If you have any questions concerning this preliminary report or any of our consulting services, please do not hesitate to contact us. Sincerely, NORTHERN COLORADO GEOTECH Prepare by: Doug Leafgr n, . President �` = Reviewed by: Gary G. Weeks, P.E. Vice President Copies to: Addressee (3) TABLE OF CONTENTS Page No. Letter of Transmittal ii SCOPE 1 SITE CONDITIONS 1 PROPOSED CONSTRUCTION 1 SITE EXPLORATION 2 Laboratory Testing 2 SUBSURFACE CONDITIONS 3 Soil and Bedrock Conditions 3 Groundwater Conditions 3 Field Test Results 3 Septic System Construction 3 GENERAL COMMENTS 4 ATTACHMENTS Boring Location Plan Logs of Borings .r. PRELIMINARY SOIL PERCOLATION REPORT PROPOSED RESIDENTIAL DEVELOPMENT HIGHWAY 37 AND WELD COUNTY ROAD 60% GILL, COLORADO NORTHERN COLORADO GEOTECH PROJECT NO. 132-03 AUGUST 8, 2003 SCOPE This report contains the results of preliminary soil percolation testing for the proposed residential "estate-style" development to be located near the intersection of Highway 37 and Weld County Road 60% near Gill, Colorado The site is located in the northwest quarter of Section 3, Township 5 North, Range 64 West of the 6th Principal Meridian. This report includes descriptions of, and geotechnical engineering recommendations relative to: • subsurface soil and bedrock conditions • groundwater conditions • septic system construction The recommendations contained in this report are preliminary in nature and based upon the results of widely spaced test borings and our experience with similar soil and groundwater conditions. SITE CONDITIONS The site is a pasture with slight surface drainage to the south. Barbed wire fences surround the property as well as dividing it into an east and west half. An existing oil tank battery is located on the southwest corner of the site. The property is bordered to the east by agricultural ground. Highway 37 is located along the west side of the site. Weld County Roads 60% and 62 border the site to the south and north, respectively. PROPOSED CONSTRUCTION As we understand it, the project will consist of dividing the property into small acreages for the construction of single-family residences that will be serviced by individual sewage disposal systems. Pickett Engineering Preliminary Soil Percolation Test Highway 37 and Weld County Road 601/2 Northern Colorado Geotech Project No. 132-03 SITE EXPLORATION A total of three test borings were drilled on July 16, 2003. The borings were drilled to approximate depths of 3 to 8 feet at the locations shown on the Site Plan, Figure 1. One soil percolation boring and one profile boring were drilled at each test location. Preliminary percolation tests were conducted in general accordance with Weld County requirements. All borings were advanced with a truck-mounted drilling rig, utilizing 4- and 6-inch diameter solid stem augers. The borings were located in the field by pacing from property lines and/or existing site features. The accuracy of boring locations should only be assumed to the level implied by the methods used. Lithologic logs of each boring were recorded by an engineering geologist during the drilling operations. At selected intervals, samples of the subsurface materials were taken by driving split- spoon samplers. Standard penetration measurements were recorded while driving a split-spoon sampler into the subsurface materials. The standard penetration test is a useful index in estimating the density of the materials encountered. Groundwater conditions were evaluated in each boring at the time of subsurface exploration, and on August 4, 2003. Laboratory Testing The samples retrieved during the subsurface exploration were returned to our laboratory for observation by the project manager. The soils were classified in general accordance with the Unified Soil Classification System. At that time, the field descriptions were confirmed or modified and an applicable laboratory testing program was formulated. Boring logs were prepared and are attached with this report. Laboratory tests were conducted on selected samples and are presented on the boring logs and attached laboratory test sheets. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. Selected samples were tested for the following engineering properties: • Water Content 2 Pickett Engineering Preliminary Soil Percolation Test Highway 37 and Weld County Road 601/2 Northern Colorado Geotech Project No. 132-03 SUBSURFACE CONDITIONS Soil and Bedrock Conditions Soils at the site generally consisted of silty sand and sandy lean clay to depths of approximately 8 feet. Summary boring logs are attached with this report. Groundwater Conditions Groundwater was encountered at approximate depths of 4 to 6%feet in the test borings at the time of field exploration and when checked on August 4, 2003. These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times, or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions. Field Test Results Field test results indicate that the clay soils vary from soft to medium in consistency. The sand soils vary from very loose to loose in relative density. Preliminary percolation testing conducted in the area of the proposed soil absorption bed is summarized as follows: Percolation Test Results Test Hole Depth Soil Percolation Rate (inches) Classification (minutes/inch) 1 36 SM 17 2 36 SC-SM 20 3 36 SM 30 The soils in the area of the proposed leach field have fair percolation rates. Septic System Construction Preliminary percolation rates of 17 to 30 minutes per inch were obtained for the site. These values are acceptable for standard leach field construction as outlined by Weld County regulations. The groundwater at the site varied from 4 feet on the southern part of the site to 6% feet near the northern end of the property. Standard septic systems appear to be feasible on the northern portion of the site. Due to the relatively shallow groundwater, engineered septic systems may be 3 Pickett Engineering Preliminary Soil Percolation Test Highway 37 and Weld County Road 60'/: Northern Colorado Geotech Project No. 132-03 necessary on the central and southern portions of the property. Prior to the start of construction complete soil percolation tests must be performed for each residence once lot and building locations are sited. GENERAL COMMENTS The analysis and recommendations presented in this report are based upon data obtained from borings performed to obtain representative subsurface conditions at the site. Variations in the soil between borings will occur. Northern Colorado Geotech should be present during construction to observe the excavation and construction procedures and confirm or modify our recommendations. The scope of services for this project does not include either specifically or by implication any environmental assessment of the site. This report has been prepared in accordance with generally accepted geotechnical engineering practices in this area at this time. No warranties, either express or implied, are intended or made. 4 .trimm ,,...... ,„,„„, „„ „,.......„,,,,,,, ,,,,,,,,at, WELD COUNTY ROAD 62 LOT A LOT B o.l is . x 5 x D w V � rm."rm." 3 �7 2S No.3 5) WELD COUNTY ROAD 60% BORING LOCATION PLAN N PRELIMINARY PERCOLATION TEST HIGHWAY 37 AND WELD COUNTY ROAD 60% GILL,COLORADO ^ FOR PICI0=TT ENGINEERING Project No. Northam 132-03 Colorado Scale: „Go Geotech Om: 7-31-03 2956 29th Street,Unit 21 Pn>Krl Npr Greeley,Colorado 80631 DML DIAGRAM IS FOR GENERAL LOCATION ONLY, Phone: (970)506-9244 AND IS NOT INTENDED FOR CONSTRUCTION PURPOCES Far (970)506-9242 FNS No. 1 LOG OF BORING No. 1 Sheet 1 of CLIENT ARCHITECT/ENGINEER Pickett Engineering SITE Highway 37 and WCR 60'/: PROJECT Gill,Colorado Preliminary Percolation Test SAMPLES TESTS O 00 ¢ n 0 LL cW W re 0 se 2 fi WW S �ll3 W >O D EC L.L1 WO 0-w 0 m yW OK OO < zo C�7 0 mz Z F ?? M 0 S a 6"TOPSOIL �. 0.5 SILTY SAND Tan, moist to wet,very loose to loose .J'. • 5— 2 _ 7.0 SANDY LEAN CLAY 3 1 SS 12 21 Tan to cream,wet,soft 8.0 BOTTOM OF BORING WATER LEVEL OBSERVATIONS Northern STARTED 7/16/03 FINISHED 7/16/03 WL 2 6.5 W.D. A‘olorado DRILL CO. Drilling Eng mu_RIG CME-55 Geotech ' A.B. 2956 29th Street,Unit 21 LOGGED BY DBC APPROVED DML T Greeley,Colorado 80631 r Measured 8/4/03 Phone: 970-506-9244 NCG PROJECT No. 132-03 5069242 Fax: 970 - LOG OF BORING No. 2 Sheet 1 of „^ CLIENT ARCHITECT/ENGINEER Pickett Engineering SITE Highway 37 and WCR 60'/: PROJECT Gill, Colorado Preliminary Percolation Test SAMPLES TESTS 0 O I. w iR w re a r.r._�nn W ce w o ru z w W a F S-=' m W rcW h a 02 0 it0IC O o to' z ?? 2 g =f 6"TOPSOIL 0.5 r.•+. - SILTY CLAYEY SAND , Tan, moist to wet, loose to medium dense e):;: V 0... 5— r : — V.— 11 , SS 12 22 8.0 BOTTOM OF BORING I WATER LEVEL OBSERVATIONS Northern STARTED 7/16/03 FINISHED 7/16/03 iI�Olorado WL 4 5.0 W.D. Geotech DRILL CO. Drilling Eng DRILL RIG CME-55 as A.B. 2956 29th Street,Unit 21 LOGGED BY DBC APPROVED DML 9 Greeley,Colorado 80631 Fi m Measured 8/4/03 Phone: 970-506-9244 Fax: 970-506-9242 NCO PROJECT NO. 132-03 • LOG OF BORING No. 3 Sheet 1 of 1 tr. CLIENT ARCHITECT/ENGINEER Pickett Engineering SITE Highway 37 and WCR 60% PROJECT Gill,Colorado Preliminary Percolation Test SAMPLES TESTS o z * c a iv W Z> W0 z U CL OW WO D: Z Li F.. ≥ > w n a r � m w �w N ❑ � a_ ❑r O KU QO 0 0 mz z zz E ❑a 6"TOPSOIL ... 0.5 SILTY SAND Tan, moist to wet,very loose to loose • 4 5.0 5— SANDY LEAN CLAY % — Gray,wet, medium 1V 6 1 SS 12 35 41 8.0 BOTTOM OF BORING WATER LEVEL OBSERVATIONS Northern STARTED 7/16/03 FINISHED 7/16/03 WL s 4.0 W.D. 1%Vlorado Geotech oRILLco. Drilling Eng DRILL RIG CME-55 u A.B. 2956 29th Street,Unit 21 LOGGED BY DBC APPROVED DML Greeley,Colorado 80631 Pi Measured 8/4/03 Phone: 970-506-9244 Fax: 970-5063242 NCO PROJECT NO. 132-03 Hello