Loading...
HomeMy WebLinkAboutMINUTES - 12182001 - C.20 I'O: BOARD OF SUPERVISORS AS THE BOARD OF DIRECTORS, I3LACKHAWK GHAD FROM: MAURICE M. SHIU, PUBLIC WORKS DIRECTOR C20 DATE: December I8, 2001 SUBJECT: APPROVE and AUTHORIZE William R. Gray and Company, as General Manager of the Blackhawk Geologic Hazard Abatement District, to execute a contract for the repair of the hillside instability, Hillside Along Conifer Terrace Landslide Repair Project, Danville area, District III. WO 5148 SPECIFIC:REQUEST(S)OR RFC:ONIMENDATION(S)S, BACKGROUND AND JUSTIFICATION I. Recommended Action: APPROVE and AUTHORIZE William .R. Gray and Company, Inc. to AWARD and EXECUTE the contract for furnishing labor and materials for the subject project to Drilling and Shoring, Inc., Antioch, California, the lowest responsible bidder, in the amount of $1,343,000.00 and at the unit prices submitted; and REQUIRE the contractor to present surety bonds for Payment and Faithful Perfonnance in the amounts of$1,343,000.00 and $1,343,000.00, respectively. DIRECT that, in accordance with the project specifications and/or upon the execution of the contract by the General Manager, any bid bonds posted by the bidders be exonerated and any checks or cash submitted for bid security be returned. AUTHORIZE the General Manager to execute contract change orders tlp to 10% of the contract amount or $134,300.00, as may be required, without further authorization from the Board of Directors. Continued on Attachment: X SIGNA'T'URE: _ RECOMMENDATION OF COUNTY ADMINISTRATOR _RECOII NIENDATION OF BOARD COMMITTEE :APPROVE OTHER SIGNATURE(S): ACTION OF BOARD ON PeZ. /j*z amo/ APPROVED AS RECOMNIENDEDXS OTHER VOCE OF:SUPERVISORS I hereby certify that this is a true and cotTect copy ofan action taken and entered on the minutes of the Board of Supervisors on the date shown. IX UNANIMOUS(ABSENT ) :AYES: NOES: ATTESTED: i ABSENT: ABSTAIN: JOHN SWEETEN,Clerk of the Board ot'Supen'isors and County Administrator Mtit:sr Ci:\GrpData\SpUist\BomdOrdcrst2001\12Decembei''BO12-13-01Awmd Sequoia-C'oniterContractAlteinate(Ioc By Ori-,'Div: Public Works(Special Districts) Deputy Contact: Ntelissa Murton(313-2252) cc: County Administrator Accounting Auditor-Cummllcr William It.Gray C� SUBJECT: APPROVE and AUTHORIZE William R. Gray and Company, as General Manager of the Blackliawk Geologic Hazard Abatement District, to execute a contract for the repair of the hillside instability, Hillside Along Conifer Terrace Landslide Repair Project, Danville area, District .I:1:I. WO 5148 DATE: December 18, 2001 PAGE 2 Ii. Financial Impact: No impact on the County General Fund. The Blackhawk GHAD is funded through revenues generated by County Service Area M-23. Sufficient funds are available for the repair, although the proposed contract will require a transfer of funds from the GHAD's reserve account. I11. Reasons for Recommendations and Background: In the fall of 2000, the GRAD initiated an investigation of potential sub-surface movement in the Sequoia Terrace/Conifer Terrace area of Blackhawk. A number of monitoring devices were installed on .Homeowner Association property to monitor groundwater levels as well as sub-surface ground movement and six horizontal drains were installed in the hillside above Conifer Terrace. The Districts geotechnical consultant, ENGEO, Inc., San Ramon, California, has been collecting and evaluating data from the monitoring devices as well as the horizontal drains since they were installed. Because of the nature of the situation, Scott Shewbridge of Shewbridge Associates, an independent Geotechnical Engineer, was retained by the GHAD to assist with evaluation of the data and to provide for peer review the work of ENGEO, Inc. Beginning in April of this year, data from some of the more sensitive monitoring devices began to detect very minor sub-surface movement. The GHAD's Geotechnical Consultants recommended that the GHAD initiate additional and more specialized geotechnical investigations in the area. A number of trenches were opened in the slope above Conifer Terrace and two large-diameter holes were drilled in the slope to permit the Districts consultants to physically inspect the sub-surface geology. In late October of this year, ENGEO, Inc. concluded that there is an area of potential instability and recommended that the District initiate a project to install a number of ground anchors to increase the stability of the slope. The District's independent Geotechnical :Engineer, Scott Shewbridge reviewed the findings and recommendations .of ENGEO, Inc. and; concurred in their findings as well as the recommended repair strategy. Both ENGEO, Inc. and Shewbridge Associates agreed that the GRAD should proceed as quickly as possible to implement the project. At the request of the GRAD, ENGEO, Inc. developed plans, specifications and a cost estimate .for the project. The proposed project was presented to the Board of Directors of the Blackhawk Homeowners Association on November 12, 2001 and discussed with the affected homeowners at a noticed public informational meeting on November 14, 2001. License Agreements providing the GHAD with sufficient rights to enter upon and repair the landslide as well as necessary indemnification are being secured from all affected homeowners as well as the Blackhawk Homeowners Association (HOA). Board Resolutions 86/370 and 98/329 define procedures related to advertising and awarding of GHAD maintenance and repair contracts. On December 3, 2001, the GHAD advertised for bids for the repair of the Sequoia-Conifer landslide repair project. Pursuant to the provisions of Resolution 86/370, three pre- qualified contractors were invited to submit bids. Bids were received and opened in the office of the General Manager on December 13, 2001. The General Manager has reviewed the Bids and recommends award of the contract. '• CI 2Oj 3 SUBJECT: APPROVE and AUTHORIZE William R. Gray and Company, as General Manager of the Blackhawk Geologic Hazard Abatement District, t� execute a contract for the repair of the hillside instability, Hillside Along Conifer Terrace Landslide Repair Project, Danville area, District III. WO 5148 DATE: December 18, 2001 PAGE 3 TV. Consequences of Negative Action: The landslide could not be repaired this season. Should the.area of potential instability begin to move, a number of improved properties would be jeopardized.