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Home My WebLink AboutMASON ST. NORTH, MAJOR AMEND. - FDP - 4-97C - CORRESPONDENCE - (13)MAR. 3.2004 8;22QM TERRACON . NO.333—. ..F 9- -- and ra DESCRIPTION (�7 Approx. Surface Elev : %,0 ft. M I - SilrySnd wirh (! a pl Black, moist, loose Tan, moist, modium dense _CTITSTMicr_AXS_pxE Tan, gold, blue, moist MOdemuly hard to hard LINES REPRESENT THE OM TYPES: ,OBSERVATIONS YG.D, i 3.9' LOG OF $ORI`i TG No. 6 I ARCM7EC'r ENGA LL I +� a Z\ pw aL6 {{yy aaJJ3C NmEa Na . IR" 2 r: rj 10 15 LINES 330 uviunv, 5-7-98 A13. lrerraicom�n_ Gam;,_ 9s -MAR. 3.2004 8:21RN TERRRCON ...... . -NO.333 -P.8 ---- LOC` OF TEST BORING NO. 6 CLaWT ARCEn7ECT/F_Mr2;BBa Wonderland Hill Development Co. Trff Cbesry sad Mason Court Development FROM= Fort Collins Colorado MArtinez FUD SAMPLES I TESTS 2 I� m N DESCRYPTION ;' Y N ir zt G w p� 9 �iR S 1@ I— q 2 1I1 Appmx.Surface Elev.:49763ft. wu H � DO. SNd Jl�\ 1.0 FML HATERTAT 4975.3 Silty Sand with Grevel Blown, tan, Say, dry to moist, loose 4.0 SILTY CLAYEY SATSn 4972.3 Tan moist, loose 31,116158 1 SS! 12" i 6 26 SANDY LEAN CLAY 3 Brown, moist, trace gravel, medium Stiff 9.0 v4967.3 2 ST 12-1 13 117 SAND 3 $S 12" 15 9 M TS' witb GRAVEL 10 $rows, to, moist, loose to medium dense I * Cobbles eucouutered with depth 15.0 4951.3 15 i 4 SS 12- 22 7 BOTTOM OF BORLNG I I �I �i THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES EE7UW SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUA-. WATER LEVEL O85iRVA710NS TUC Irerracon BOR DST' R`B= lD-Li-01 wL g DRY w.a _9 soRuxTODAmeBD 10-11-01 WL CME 55 FOREMAN AS LVI Water checked 4 s A.B. APPROVED DAR Ion x 20015=6 MAR. 3.2004 8:2OAM TERRACON ♦ipfi �r F. '♦yam-.�r�♦.�� r ♦ +� ;I 1 �4 1♦ 10 6 aosamr> — o C R R Y clr a o S T R E E'`; T o �0 LEGEND } TEST BORING NOs. 1-7 NOTE: GROUNDWATER CONTOURS WERE ESTIMATED USING THE "SURFER" Y DRILLED 1O/1D/O1 PROGRAM FROM GOLDEN SOFTWARE BASED ON DATA COLLECTED FROM TB NOs. 1-7. ACTUAL CONDITIONS TEST BORING NO.5 DRILLED 5/7/98 MAY VARY. PROJECT A 20965081 ESTIMATED GROUNDWATER ELEVATION FIGURE 3: GROUNDWATER CONTOUR MAP gg74 MARTINEZ PARK CHERRY STREET k MASON COURT XWLOPMENT �♦ ESTIMATED DIRECTION OF FLOW FORT COLLINS, COLOR.ADO ►rojwt wnpr. . DAR lac Projw No. 20015 opgneq or. [4978.31 TOP OF CASING ELEYA71CN DAR rracan Smir. (4964.8) GROUNDWATER ELEVATION — 1/16/02 OAeciW BK DAR 301 N. Howes Street Fort Collins. Colorado 80521 O'~' 10/1 Appma By. Drown Sp DAR '�AND 15 NOT INTENOW FORLDONSTRUCTIIOONN PURPOSES. F11r Nanr. 5226fIC3 IFiYun Na 3 .MAR. 3,2004 6:20AN TERRACON N0.333 "'—P.6- _.._.. t Geotechnical Engineering i._port - Addendum No. 1 Terracon Staff Project Review Comments Response Martinez Park P.U.D. - Cherry Street and Mason Court Fort Collins, Colorado Project No. 20015226 Page 4 groundwater levels elevate above previously recorded elevations and be intercepted by the interior perimeter drainage systems, the cone of influence, will primarily be within the building footprtnt and within the property boundaries of the site. Based on the on -site soil conditions, it is our opinion adjacent properties would not impacted. 8. The design details such as the pipe diameters, subdrain terminator, and point of discharge for the interior perimeter drainage system for Building C are being considered by Shear Engineering Corp. in the utility design plans. 9. The Log of Boring for Test Boring No. 6 drilled on May 7, 1998 and the second Log of Boring No. 6 drilled on October 11, 2001, are included with this report for comparison purposes. The above referenced information addresses the issues and concerns presented in the Staff Project Review's letter dated December 5, 2001. We appreciate being of service to you in the geotechnical engineering phase of this project, and are prepared to assist you during the construction phases as well. If you have any questions concerning this letter or any of our testing, inspection, design and consulting services please feel free to contact us. Sincerely, TERRACON Prepared by: David A. Richer, P.E. Geotechnical Engineer/Department Manager Reviewed by: Doug J. Jobe, P.E. Office Manager Enclosure: Groundwater Contour Map (Piezometric Surface Diagram) - Figure No, 3 Log of Test Boring No. 6 drilled 517/98 and Log of Boring No. 6 drilled 1Oil 1101 Copies to: Addressee (3) Wolff -Lyon Architects: (2): Mr. Korkut Onaran Shear Engineering Corporation (1): Mr. Brian Shear ,MAR. 3.2004 8:19AM TERRACON IJO.333 "-P.5' Geotechnical Engineering R,, art —Addendum No. 1 Terracon Staff Project Review Comments Response Martinez Park P.IJ.D. — Cherry Street and Mason Court Fort Collins, Colorado Project No. 20015226 Page 3 levels would stil! be below the lower level siab of Building C. With this information, there was no need to determine and/or evaluate flow rates. 3. The source of groundwater in this area is typically a natural reoccurring hydrological cycle generated from surface water runoff and/or volume of flow of the Cache La Poudre River, which is located north of the project, Groundwater is typically recharged by incremental precipitation; influence by wetlands andior from constructed recharge basins. The groundwater on the site is part of a shallow aquifer of the Denver Basin and is not pat of a protective groundwater basin, 4. The purpose of the perimeter drainage system is to prevent groundwater and/or surface water infiltration from entering and impacting the lower level of Building C. Based the groundwater levels and the conceptual development plan for the site, there is no requirement for permanent dewatering, Therefore, if wells were present, the wells would not be impacted by the proposed development; thus a review was not performed, Terracon could conduct a review of possible wells, if requested. 5. Presently, the quality of the groundwater should not be impacted due to potential contamination of nearby industrial utilization. The site is not located within an industrial area. The possibility of groundwater contamination at the site at this time is believed to be minimal. Based on our review of the proposed site development plans, it is our opinion the groundwater quality will not be impacted by the proposed development and associated infrastructure. 5. To reiterate, the perimeter drainage system for the proposed Building C, was recommended to prevent potential groundwater fluctuations and/or surface infiltration from entering and impacting the lower level area. Should groundwater levels elevate above the recorded levels the interior perimeter drainage systems would intercept the fluctuations prior to impacting the lower levels. The discharge from the drainage system/sump pit would empty into a solid 8-inch diameter PVC pipe, sized by Shear Engineering Corp„ situated within the sewer trenches located within the proposed paved areas and/or back of lot. This 8-inch diameter solid PVC pipe is to collect the discharge from Building C and not de -water and/or lower groundwater levels. As a standard practice of the industry for construction of perimeter drainage systems, we recommended that a 4-inch diameter perforated drain line be placed around the perimeter of the lower foundation levels with cross -drains as stated in the report and discharged into a sump pit or daylight to the north beyond the foundation of Building C. The recommendations for the construction of the subdrain are presented on page 9 of our initial report under the subheading "Lower level Construction" with additional information being provided in this letter as to the intent/purpose of the interior perimeter drainage systems. 7. The cone of influence as a result of the dewatering and/or prevention of groundwater impacting the lower level of Building C� is minimal to non-existent. Tc reiterate, we are not providing permanent dewatering for the site to allow for the proposed lower level construction. Should MAR. 3. 2004 8: 18AM TERRACON N0. 333 ---P. 4-- Geotechnical Engineering k�,,ort—Addendum No. 1 Terracon Staff Project Review Comments Response Martinez Park P.U,IJ, — Cherry Street and Mason Court Fort Collins, Colorado Project No. 20018226 Page 2 Groundwater, as stated in our report, pages 4 and 9 was encountered et approximate depths of 9 to 18-feet below existing site grades. Based on the review of the civil engineering drawings, street and/or paved area subgrade elevations are well above the 3-foot criteria as ovell. Therefore, in accordance with the LCUASS criteria, the developer/designer is not required to perform a "subsurface water investigation" for the site. However we will provide the necessary/appropriate information as requested. I. The site does not contain irrigation ditches, wetlands or other features, which would be impacted due to the proposed development, thus the reason for not being identified on the Site Plan. 2. Based or our review of the site and continual monitoring of the groundwater fluctuations, it is our opinion the potential high water levels would be expected to be approximately 1 to possibly 2- 1/2-feet higher than reported in our study presented In the report dated October 23, 2001, However, we will continue to monitor the groundwater piezometers and will provide up to date groundwater monitoring episode reports to further evaluate the potential fluct labon rise of groundwater. We conducted a piezometric monitoring episode on January 16, 2002. Groundwater levels as recorded on this date were measured at approximate depths of 10-1/2 to 13-1/2-feet below existing site grades, well below the required 5-foot criteria as specified in LCUASS Section 5.6. The estimated piezometric surface was developed for the site based on the groundwater measurement data collected on January 16, 2002. The groundwater contour map for the site based on the piezometric data on January 16, 2002, is included with this addendum report as Figure 3. The piezometric surface was estimated using linear interpolations between piezometers and was based upon groundwater elevations in each piezometer. As illustrated from Figure 3, the groundwater flow shifted from when originally reported, and appears to be in the south to slightly southeast direction away from the Cache la Poudre River, which is located north of the property boundary. The water table as indicated on Figure 3 is still 2 to 4- feet below proposed finished floor elevation of Building C. The primary purpose of requiring an interior perimeter drainage system around the lower level of Building C was to provide a mechanism of assuring that the lower level will remain dry should groundwater levels become elevated. The designed intent of the perimeter drainage system was to intercept flow prior to entering the lower level of Building C. As stated in our report page 9, "Based on our review of the proposed civil engineering drawings prepared by Shear Engineering Corporation, the proposed finished floor (FF) elevation of Building C is 4979.5. Assuming the lower level slab will be placed approximately 11 to 12-feet below FF elevations, and correlating with the groundwater piezometric surface flow diagram. Figure 3, the lower level slab will be 2 to 4-feet above the existing water levels." Therefore, if groundwater levels were to fluctuate on the order of 1 to 2-1/2 feet above previously recorded measurements, groundwater MAR. 3.2004 8:18AN TERRACCN N0.333" —F .3 January 16, 2002 Wonderland Hill Development Company 745 Poplar Avenue Boulder, Colorado 80304 Attn Mr. Jim Leach Irerracon 30, North Mowers • RID, Box sm Fort C4111nG. Colomdo 9042 -OR3 (970) 484.03.99 Fart' (070) 484-C454 Re: 'Response to City of Fort Collins — Staff Project Review — Addendum Report No. 1 Proposed Multi -Family Residential Development Martinez Park P.U.D. — Cherry Street and Mason Court Northeast 4/4 of Section 11, Township 7 North, Range 69 West Fort Collins, Colorado Terracon Project No. 20015226 Terracon conducted a geotechnical engineering exploration for the proposed Martinez Park P.U.D. — Residential Development project located at the northwest comer of Cherry Street and Mason Court in north Fort Collins, Colorado on October 11, 2001. For further information and findings thereof, please refer to our "Geotechnical Engineering Report" dated October 23, 2001,-Project No. 20025225. The intent of this letter is to provide supplemental information and/or additional recommendations with regards to the "Staff Project Review" comments dated December 11, 2001, and sent to Terracon via facsimile from Mr. Korkut Onaran of Wolff -Lyon Architects, of Boulder, Colorado. The format of this letter will present the Staff Project Review (SPR) comments and/or concerns followed by Terracon's response. • SPR Comment No. 153.- Topic Geotechnical Report: The Subsurface Report does not address - issues as outlined in LCUASS 5.5. 1. Site location map does not address irrigation ditches, wet lands or other features. 2. Where are flow rates addressed, potential high water levels? 3. What is the potential source of the groundwater? 4. Are there any existing wells in the area?: 5. Address ground water quality. 6. Address water flow calculations, how was the pipe sized? What are the recommendations for construction of subdrain? 7. Identify the cone of influence as a result of the dewatering. S. Where will subdrain terminate? 9. Where is the log of the second boring number 6? Terracon's Response: Larimer County Urban Area Street Standards (LCUASS) — Section 5.6 A. Criteria states" If groundwater is encountered within 5-feet of the original ground surface, a subsurface water investigation report shall be submitted for approval by the Local Entity Engineer. B. Requirement Waiver states "This report requirement may be waived if the Applicant and Designer certify that the street subgrade elevations will be a minimum of 3 feet above the "maximum" predicted (seasonal highest) water table. " Aritane ■ A(kinsas r CaElornia ■ Colorado ■ Georgia a Idaho ■ Illlm+s ■ IOWA ■ Kansas ■ Kentucky ■ M,rnnosota N Mlesourl fdontana ■ Nebr"VA N N"a ■ New Moxico r North Ca--•ollm N Cklahoma 07snneoso ■Taxi ■ Utah ■ Wisconsin ■ Wyoming ConeultIng Englnsam 3 Scientists Slmco tges www.telTacm.com -MAR. 3.2004 8:17AN TERRRCON N0.333 P. March 2, 2004 Shear Engineering 4836 South College Avenue Fort Collins, Colorado 80525 Attn: Mr. Brian Shear, P.E. Irerracon 301 Ncrih Howes - F..O, Box 503 Fcn Collins, COWILdo 805114503 (970) 484-0 69 FOX (870) 484-0464 Re: Response to City of Fort Collins — Staff Project Review — Resubmitted from 1/16102 Proposed Multi -Family Residential Development Martinez Park P.U.D. — Cherry Street and Mason Court Northeast'/. of Section 11, Township 7 North, Range 69 West Fort Collins, Colorado Terraoon Project No. 20015226 On March 1, 2004, we were informed by Shear Engineering Corporation of Fort Collins, Colorado to provide a. response to the Staff Project Review Comments for the above referenced project. A copy of the Pending Number 153 — Geotechnical Report was sent to Terraoon via facsimile on March 2, 2004. Terraoon previously provided a response to these comments on January 16, 2002. Enclosed with this letter is the response from a geotechnical engineering viewpoint in regards to the pending items. It is our intent that the enclosed information addresses the issues and/or concerns; (i.e. Geotechnical Report Comments) presented in the Staff Project Review Comments. Please notify us if additional data and/or information are required to satisfy the staff. We appreciate being of service to you in the geotechnical engineering phase of this project, and are prepared to assist the project team during the final design stages and the construction phases as well. If you have any questions concerning this letter or any of our testing, inspection, design and consulting services please feel free to contact us. Sincerely, TERRACON David A. Richer, RE. Geotechnical Engineer/Department Manager Enclosures: Initial Response Letter dated January 16. 2002 Copies to: Addressee (5) AN"one ■ Arkansas ■ Ca*rnla ■ c010re0e 0 Gec-19W ■ lloho ■ Rnois ■ lows ■ Kan= ■ Kentucky ae wrwota ■ Mi=un Montano ■ Nebraska • Nevada ■ New MoxkO 0 North Carolina ■ OXW"a gTennecaee ■ Texuc a Vtah O Wisconsin ■ Wyoming Cwmmng Englnows b Bclentlets Sines tees www.tatacon.com .MAR. 'J.2004 8:17AN TERRACON NO.333 P. Fax Transmittal Date: March 3, 2004 To: Brian Shear and/or Seth Tourne Company: Shear Engineering Corporation Fax Number: 970 282 — 0311 From: Dave Richer (Geotechnical Engineer/Department Manager) Company: Terracon 301 North Howes Street Fort Collins, Colorado 80521 (970) 484-0359 Fax Number: (970) 484-0454 e-mail Address: nnrichcrerracoa.com Subject: Staff Review Response Letter for Mason Street North Project Total No. of (including this sheet) Pages: Comments: Enclosed please find a copy of our geotechnical engineering response letter for the above -referenced project. These are the same comments that were previously responded to in January of 2002. I'm re -submitting the same letter. Was this letter ever presented to the staff in January of 2002???????? Thank you very much for your consideration of using Terracon, we look forward to working with you on this project and future projects as well. -Any questions Please call. Thanks.... ...Dave 1 rracon Delivering Success for Clients and Employees www.terracon.com