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HomeMy WebLinkAboutEBA Wastechnologies 1992-11-12; Amendment 3 1995-05-18 ActiveC��r_ LL t 11 2`1,2 -A3 CITY OF UKIAH AMENDMENT TO MASTER AGREEMENT FOR PROFESSIONAL CONSULTING SERVICES, DATED NOVEMBER 12, 1992 TERMS AND CONDITIONS All terms and conditions of Master Agreement for Professional Consulting Services between City of Ukiah and EBA Wastechnologies, dated November 12, 1992, shall remain in force and effect except as modified by this and previous executed amendments. AUTHORIZATION Upon execution of this amendment, consultant is authorized to perform the work described under "Scope -of- Work" of this amendment, on a time and expense basis, not to exceed the total amount of compensation indicated for the work task. SCOPE -OF -WORK The Master Agreement Is hereby amended by the addition of the following: Consultant shall perform an investigation of on -site clay borrow sources at the Ukiah Landfill. The Investigation will be focused on the main borrow area located near the landfill entrance and will involve excavating several test pits on the western slope; the collection of clay material from the test pits, for testing; and the submittal of a final report summarizing the field investigation findings, results of the laboratory testing, and a rough volume estimate of available day sources and overburden to be removed. Soil testing will Include sieve analysis, atterberg limit, compaction, and permeability testing. This scope of work Is also Identified In consultant's proposal, dated May 8, 1995, for the limited investigative work denoted as Option 2. The Proposal was submitted in response to City's Request for Proposal, dated April 18, 1995. COMPENSATION Compensation for the work of this Amendment shall be made on a time and expense basis not to exceed a maximum total compensation of $8,000. Labor rates and expenses shall be those identified on the consultant's current labor and expense schedules. Table 2, Option 2, as shown in consultant's proposal, is for estimation purposes and costs for Individual work Items may be more than, or Tess than, the costs indicated. EBA WASTECHNOLOGIES Duane ut of r, Principal 4:PW:EBA.Agm CITY . UK AH oug , or es Date ager W S'TECHNOL OG /ES Engineers & Environmental Consultants May 8, 1995 Mr. Rick Kennedy, Director Public Works Department City of Ukiah 300 Seminary Avenue Ukiah, CA 95482 RE: UKIAH SANITARY LANDFILL, BORROW SOURCE INVESTIGATION EBA PROPOSAL 132 -95 Dear Mr. Kennedy: E13A Wastechnologies is please to submit this Proposal for the investigation of on -site clay borrow sources at the Ukiah Landfill as requested in your letter dated April 18, 1995. The City of Ukiah requires approximately 76,000 cubic yards of clay material to construct the clay barrier layer of the final closure cap and an unspecified quantity for ongoing construction of operational berms. An additional 33,000 cubic yards has been requested by the City of Willits for their closure requirements. The scope of this proposal focuses on the main borrow area located near the landfill entrance. Soils exposed in the borrow area consist of grey sandy clay which grades upwards into weathered brown sandy clay. This unit is overlain by a brown clayey silt which forms the hilltop above the borrow area. Previous work performed by EBA (Appendix F, Revised Preliminary Closure Plan, August 1994) indicates that the grey /brown clay currently being excavated from the borrow area meets requirements of the California Code of Regulations, Title 23, Section 2541 for construction of low permeability clay liners. It is believed that the grey /brown clay exists in quantities which are sufficient to meet future soil requirements. However, existing cut slopes in the borrow area have become excessively steep and access to additional clay materials will likely require the removal of significant volumes of the overlying clayey silt unit. EBA understands the concerns the City has regarding the removal of overlying materials and vegetation, as well as the consequences such operations may have on the logistics of ongoing haul operations. An understanding of the lateral and vertical extent of the grey /brown clay material is essential before a borrow materials excavation plan can be developed which would strive to maximize the amount of clay material obtained with the least amount of effort involved L: \PHOPOSAI .\1995113?- 93\CI.AY -HOR.r rK ERA Mame-luwlorlra 825 Sonoma Avenue, Suite C Santa Rosa, California 95404 (707) 544 -0784 FAX (707) 544 -0866 11344 Coloma Road, Suite 245 Gold River, CA 9567() (916) 852 -6800 FAX (916) 852 -0866 Also Las Vegas, Nevada Mr. Rick Kennedy May 8, 1995 Page 2 in its removal. Exposures in the active face of the borrow area indicate that the contact with the overlying clayey silt is at an approximate elevation of 900 feet (MSL). Limited geologic information suggests that the contact dips gently towards the southwest at an angle of 6 to 10 degrees. Additional information is required to verify the orientation of the contact and locations where the contact may daylight along the western slope of the hill, behind the borrow area. The western slope of the hill behind the borrow area appears to be the most likely area for sourcing future borrow material. Slopes on this side of the hill are considerably flatter than those on the east side and are not visible from landfill entrance or properties to the east of the site. Finally, the overburden of clayey silt material is believed to be thinner on western sideslopes. For these reasons, proposed field investigations will concentrate on the west side of the borrow area. As requested, we have prepared two cost estimates. The first cost estimate (Option 1, Table 1) includes the scope of work which would be necessary to conduct a field investigation using standard geotechnical field methods and laboratory testing. We proposed drilling four to six borings on the hilltop above the borrow area and on the western slope in order to define the contact and collect samples of the underlying clay material. In conjunction with drilling, several test pits would be excavated on the western slope with a backhoe to determine where the contact daylights and to collect samples of the clay material. Approximately nine samples would be submitted to a geotechnical laboratory for sieve analysis, atterberg limit, compaction and permeability testing to determine their suitability for use in construction of the low permeability clay layer. Based on the results of previous testing, samples submitted for permeability testing will be remolded at 90 percent relative compaction (Modified Proctor) and varying moisture contents (approximately 2 to 4 percent above optimum). EBA will determine total soil requirements including daily cover, berm construction, final cover requirements for the City of Ukiah landfill and additional quantities as requested by the City of Willits. EBA will then estimate of the quantities of overburden and clay materials which must be excavated. This information, along with the geotechnical field and laboratory data, will allow the City to prepare a borrow excavation and grading plan. EBA would also be available to provide engineering support to City personnel during development of a conceptual borrow excavation or grading plan. EBA will prepare a report which will discuss results and summarize findings of the borrow investigation. The cost to perform these services, including geotechnical borings, backhoe trenching, laboratory testing, volume estimates and final report, is estimated at $18,509. The second cost estimate (Option 2, Table 2) involves a more limited scope of work which includes the effort necessary to produce the minimal amount of data required to assess the clay borrow source with some degree of accuracy. The data collected with this limited scope may l.: \PROPOSAL \1995 \132 -95 \CLAY- BOK.I:I R EM Wmsrrlwologlu Mr. Rick Kennedy May 8, 1995 Page 3 not be sufficient for the City to develop a borrow excavation and grading plan. Any such plan would be conceptual and would need to be periodically revised as borrow operations advance into the hillside and reveal additional geologic information. The uncertainty involved with a limited scope of work may hinder the economic development of the borrow area and may prove more costly to the City in the long run. For the limited scope of work, EBA proposes excavating several test pits on the western slope with a backhoe to collect samples of the clay material and determine where the contact daylights. Approximately four samples would be submitted to a geotechnical laboratory for sieve analysis, atterberg limit, compaction and permeability testing as described above. EBA would prepare a final report summarizing the field investigation and results of laboratory testing. A rough volume estimate of available clay sources and overburden would also be provided based on the results of the limited data collected in the field. EBA could also provide engineering support to City personnel during development of a conceptual borrow excavation or grading plan. The cost to perform these services, including backhoe trenching, laboratory testing, volume estimates and final report, is estimated at $7,916. We look forward to working with you on this project and will be pleased to discuss any questions you may have. Sincerely, EBA WASTECHNOLOGIES Chris Brummer Geologist /Design Engineer aor Damon F. Brown, R.G., C.E.G. Senior Geologist L: \PROPOSAL \1995 \132.95 \CLAY- UOR.LTR E114 Wmi<cMofogle, TABLE 1 UKIAH LANDFILL BORROW STUDY INVESTIGATION OPTION 1 - COST ESTIMATP. TASK EBA DIRECT LABOR GEOTECH. SERVICES LAB &MISC. COSTS TOTAL COST TASK A: REVIEW EXISTING GEOLOGIC INFORMATION $700 $700 TASK 13: FIELD INVESTIGATION OF BORROW AREA FIELD ('REPARATION $260 $260 GEOTECIINICAL DRILLING $1,760 $4,416 $5,207 $11,383 BACKIIOE TEST PITS $520 $863 $180 $1,563 TASK C: REPORT EVALUATE SOIL REQUIREMENTS $440 $440 REVIEW FIELD I)ATA $1,060 $1,060 ESTIMATE VOLUME OF CLAY $880 $880 PREPARE REPORT $2,223 $2,223 PROJECT TOTALS : $7,843 $5,279 $5,387 $18,509 TABLE 2 UKIAII LANDFILL BORROW STUDY INVESTIGATION OPTION 2 - COST ESTIMATE TASK EBA DIRECT LABOR GEOTECH. SERVICES LAB & MISC. COSTS TOTAL COST TASK A: REVIEW EXISTING GEOLOGIC INFORMATION $570 $570 TASK I3: FIELD INVESTIGATION OF BORROW AREA FIELD PREPARATION $130 $130 GEOTECIINICAL DRILLING $2,420 $2,420 BACKHOE TEST PITS $650 $863 $90 $1,603 TASK C: REPORT EVALUATE SOIL REQUIREMENTS $440 $440 REVIEW FIELD DATA $700 $700 ESTIMATE VOLUME OF CLAY $570 $570 PREPARE REI'ORT $1,484 $1,484 PROJECT TOTALS : $4,544 $863 $2,510 $7,916 PI 32C ST. W K3 4ah 300 SE 'VE., UKIAH. CA 95482 -5400 • ADMIN. 707/463 -6200 • PUBLIC SAFETY 463-6242/6274 • FAX N 707/463 -6204 • April 18, 1995 Mr. Damon Brown EBA WASTECHNOLOGIES 825 Sonoma Avenue, Suite C Santa Rosa, California 95402 • RE: REQUEST FOR PROPOSAL TO PROVIDE CLAY AVAILABILITY STUDY AND REPORT FOR CITY OF UKIAII LANDFILL 1)car Damon: Your proposal to provide appropriate field services and a written report of findings and recommendation regarding the availability and /or location of on -site clay sources with sufficient quantity and quality of material for the purpose of capping the landfill pursuant to Title 14 and Subtitle D is requested. Pursuant to the Preliminary Closure Plan, it is estimated that 75,900 cubic yards of clay will be required to construct the barrier Iayer of the final cap system. It is assumed that Ilse estimated quantity is based on a one loot Iayer of barrier over the exposed surfaces of the landfill; the projected area of 40 acres at one loot depth requires 65,530 cubic yards. As you know, we currently use on -site clay material to construct the outside beret or sloped landfill )'ace as well as Ibr the inside berm against the existing hills on the south side of the active burial areas; the inside perm is constructed vertically from the existing footprint and the outside berm at a 2 :1 slope. Soil materials not meeting the requirements of the clay material are placed behind the inside berm or on the natural hillside of the berm. These berms are constructed with a scraper to a height of 4 .to 5 feet above the active landfill surface and then cut back on the active landfill side until a width of 4 feet at the top of the berm is achieved. Since we do not currently have a QA Program for the cap construction, the clay material now being placed on the outside face does not at this time qualify as a barrier. It is my plan that at the time of closure and subsequent to the implementation of the QA Program, the face of the outside harriers constructed of clay can be scarified and compacted to the required densilication and the addition of clay over those berms so constructed will not he required. To my knowledge, only those. berms constructed since the Spring of 1994 were constructed as described above. To date, I do not have an estimate of the amount of clay that will be required to construct the outside and inside berms on the remaining three (3) burial areas. The three (3) burial areas are the "west tipping" area in the vicinity of gas wells 4 and 3, the "east tipping" area adjacent to and west of the new scale house location, and the "table lop" area where the gate house was formerly located. Besides meeting our own clay soil needs, the City of Willits has inquired if the City of Ukiah can provide approximately 33,000 cubic yards litr their closure needs. It is anticipated that the Willits landfill will be closed in January of 1997. ylp Air, its,0 re, t Based on my site inspections of the two borrow areas, it is my opinion that the remaining source of clay (grey sandy clay) that will most likely provide the amount of material needed as described above, can be found beyond the existing southern cut face in the east or main burrow area. It is also my belief that it will be necessary to remove the hill top to gain access to this supply. The soil material above the clay layer appears to be siltstone and can be used for daily cover or as backlill material behind inside clay berm barriers. Considering the amount of the siltstone above the clay, 1 believe it is necessary that we begin "top removal" now. Although top removal will increase the haul time for soil cover today, the cost of removal at the time of closure will be more costly and unproductive. Top removal will also require the removal of many trees and it is my desire that a clay availability study be performed to either confirm or disprove my position. In our current budget, we have $8,000 available for the requested study and report. Obviously, it is my hope that the budgeted amount can adequately finance the necessary field surveys that will produce the minimal amount of information required to assess the clay source with some degree of accuracy. I ask that your proposed scope -of -work include the minimal amount of effort that will produce sufficient information. Your proposal should also include a time. frame within which the work can be completed once a notice to proceed is given. I prefer that the proposed compensation be based on a time and expense not to exceed basis. I also ask that we receive your proposal no latter than May 8, 1995. Please call me at your most earliest convenience should you require any clarification or further information which will assist you in making a proposal. t , erely, 1 ick ' . Kennedy Director of Public Works /City Engim►(eer KIIK:KK R:1\I.ANI IFII.1. I.IIKOWN.7