REMOVAL_2007 PIPING - Laserfiche WebLink

Home Browse Search

v %me ..i The UST piping removal permit application was submitted to the SJCEHD and subsequently approved on October 5, 2007. A copy of the permit is included in Appendix A. Concrete and r asphalt were removed using a backhoe equipped with a 7,000-pound hydraulic hammer. The concrete and asphalt were temporarily stored onsite in a roll-off bin pending offsite disposal. Soil was excavated by backhoe and hand digging and was stockpiled on the pavement adjacent to the excavation. r Excavation revealed four metal pipes in one trench. The piping measured approximately 2- inches in diameter and were oriented generally northeast to southwest (Figure 3). The pipes were parallel to one another in the trench and were situated in two groups of two, one set above the second set. The upper piping extended the entire length of the trench (approximately 17 feet), one of which was broken at a bend near the southwestem-most end. The lower third and fourth pipes, extended from the southwestern-most end of the trench to a point approximately one-third and one-half the length of the trench, respectively. The piping which had a length equal to one-third of the trench had a break at a bend near the southwestern end. Each metal pipe showed evidence of corrosion and holes in various locations along the length. The ` northeastern ends of the piping were beneath the concrete slab at an approximate depth of one foot BGS, adjacent to the southern side of the former pump island excavation. The southwestern ends of the piping were at an approximate depth of 1.5 feet BGS, near the northern edge of the former 6,000-gallon gasoline UST excavation. Inside the former gasoline UST excavation, the four pipes extended downward into the backfill. The piping was likely bent downward and toward the northern edge of the gasoline UST excavation to allow removal of the 6,000-gallon USTs or during subsequent soil excavation activities performed in 1987. The breaks (noted above) near the southwestern ends of the piping appeared to be due to this ` bending of the piping. Approximately one cubic yard of base rock backfill was excavated from the 1987 excavation to allow removal of the southwestern ends of the piping. Field observations did not identify petroleum hydrocarbon impact in the surrounding soil. A photoionization detector (PID) was r. used to monitor for organic vapors in the breathing space and inside the excavation area. No PID readings were detected above background levels. The UST piping was removed on October 5, 2007, using a backhoe and hand tools under Mr. von Rie's supervision. The piping was saw-cut into short segments and the pieces were temporarily stored onsite in a Department of Transportation(DOT) approved 55-gallon drum. SLAIR 2007.11 Pipline Removal Report 2