MTA Division 6 Groundwater Monitoring and Reporting, Venice, California
Los Angeles County Metropolitan Transportation Authority (LACMTA)
Field visits to sites, Groundwater sampling, Well monitoring, Quarterly report preparation, Evaluation of results, Presentation of conclusions
This program provides data and evaluations necessary to satisfy the Regional Water Quality Control Board’s (RWQCB) quarterly groundwater monitoring and reporting requirements. DRC supported and implemented the existing Health and Safety Plan to protect all personnel and subcontractors at the site. This included quarterly monitoring and sampling of six groundwater monitoring wells at the site; beginning in November 2003 (4th quarter) and continuing for three quarters (three rounds of monitoring and sampling). Each well was monitored for depth to groundwater and for floating hydrocarbons using an electronic well sounder and interface probe. Groundwater levels were measured to the nearest 0.01-foot relative to the top of the well easing to conform with procedures for previous measurements. Groundwater levels range from approximately 19 to 25 feet below ground surface. A new disposable bailer was used to collect groundwater samples. Each sample was decanted into sample jars. Natural attenuation parameters, including pH, specific conductance, temperature, dissolved oxygen, and oxidation-reduction potential, were monitored in the well after purging and sampling procedures. DRC prepared quarterly reports for groundwater monitoring and one annual report after the 4th quarter 2003 monitoring event. The draft quarterly groundwater monitoring reports described field procedures, measured groundwater levels and water quality parameters during well purging, summarized laboratory analytical results, discussed results, and rendered conclusions. Maps were included that provided groundwater contours as well as the distributions of detectable groundwater contaminants. DRC prepared and submitted final reports to MTA by the 13th of the month following the end of each calendar Quarter.