SU0004072 SSNL - Laserfiche WebLink

Home Browse Search

Bright Development 7851.4.001.01 APN 240-040-02, 24832 South Lammers Road July 20, 2007 SOIL SUITABILITY STUDY Page 4 4.0 GROUNDWATER INFORMATION 4.1 Depth and Gradient of Groundwater Based on revi a well permit for 24801 S. Lammers Road, de th to groundwater was first encountered 54 f et below the ground surface (b On my 20, 2007, we measured the depth ell to groundwate in existing well on the Propert at 25.1 f et below the top of the well casing, or approximate) 23.5 eet below the surr 1 and s rface. Based on review of a water level record f a ell located wit 1/4-mile southwest of the Property (State well no. 02SO4E25J00I M), groundwater has historica y varied between 20 and 30 feet below ground surface int eneral area. Based on topographic gradient and groundwater basin geometry, shailovv groundwater is expected to flow to the northeast. 4.2 Potential Groundwater Contamination Issues The general area is used for agricultural and rural residential use. As such, the potential exists j for groundwater to be impacted with nitrate from animal manure and septic systems, and from agricultural chemical application, primarily dibromochloropropane (DBCP). 4.3 On-Site Well Sampling On July 18, 2007, we collected a sample from the on-site domestic-use water well for nitrate and/ DBCP analysis. The on-site well had an eight-inch-diameter steel casing with a sanitary seal. A jet pump was located adjacent to the well and was plumbed to a I-inch-diame water line. N sampi\ng port was at the wellhead. A water sample was collected from a spigot located on - th oi�of the house within 20 feet of the well. i 4.4 Water Sample Analyses The water sample was analyzed for nitrate and DBCP by EPA Methods 300.0 and 8211, �00 I� respectively. The analytical 1 oratory performing the analyses was Test America (formerly STL San Francisco), a State rtifie analytical labor located in Pleasanton, California. Theell analytical results indicated nitrate concentration f 48 1 illigrams per liter (mg/l) and DBCP below the practical quantific ion I it of 0.00001 n 4.5 Sample Collection and Handling Prior to sample collection, the water spigot was turned on and water was allowed to flow for 10 minutes after the well pump had turned on. Sample containers supplied by the laboratory (1-liter poly for nitrate and three 40-m1 glass VOA vials for DBCP) were then filled. The VOA vials were filled by trimming the water flow to a dribble and carefully canting the vials to