FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

Efts Consulting-Engineering-Remediation 10324 Placer Lane Suite 200 Sacramento,CA 95827 (91 )362-71ou 6 June 12, 2000 FAX(916)368160 Project No. 8728-010 http://www.erisrcom Ms. Lori Duncan - Senior REHS .� San Joaquin County Public Health Services --- Environmental Health Division .. 304 East Weber Avenue, Third Floor Stockton, CA 95202 Subject: Well Destruction 26500 Nowell Road Thornton, California, 95686 Dear Ms. Duncan: ENSR is submitting this report, documenting domestic well and monitoring well destruction (four wells total) at the above-referenced site (Figure 1), on behalf of Pamela Lopez. The well destruction and subsequent report preparation were conducted under the review and supervision of the undersigned California-registered professional geologist. Woodward Drilling Company, of Rio Vista CA, performed the well destruction. Copies of California Department of Water Resources (DWR) well completion reports are included as Attachment 1. Original well completion reports were forwarded to the DWR as required. On May 1, 2000, ENSR oversaw the video logging of the domestic well on site. Video logging was required due to the lack of well completion information necessary for proper well destruction. On May 4, 2000, ENSR and Woodward Drilling Company personnel returned to the site to destroy the domestic well. The driller encountered 8 518-inch-diameter conductor casing at the surface and did not possess equipment large enough for that diameter. Consequently, the Environmental Health Division granted verbal authorization to destroy the well by grouting to the surface. On May 12, 2000, ENSR oversaw the grouting of the domestic well to the surface. The top 1.5 feet of casing were cut off and the excavation was filled with soil. On May 3, 2000, ENSR personnel oversaw the destruction of three groundwater monitoring wells (MW-1, MW-2 and MW-3) (Figure 2). The three monitoring wells were destroyed in accordance with DWR Bulletin 74-90, Section 19 - Requirements for Destroying Monitoring Wells and Exploration Holes. The wells were constructed and maintained in accordance with these standards and located in an area of potential contamination, therefore the wells were destroyed according to state guidelines. The monitoring well depths were verified using a water level indicator. The wells were drilled out to their total depths using 8-inch diameter hollow stem augers with an 8'/-inch-diameter bit. The casings were destroyed during over-drilling operations. Filter pack and other drill cuttings were placed in 55-gallon DOT drums. The well bores were then grouted to the surface with Type 1-I1 cement through a tremmie pipe. L f-NSR18728101018728010.ALT.doc