WORK PLANS - Laserfiche WebLink

Home Browse Search

Central Valley Regional Water Quality Control Board 6375.4.002.01 Yosemite Avenue Properties December 6, 2004 WORK PLAN FOR GROUNDWATER STUDIES Page 3 Instrumentation, Inc. water level logger model number WL15 to automatically record water levels in each of the monitoring wells. The WL15 consists of a data logger connected to a submersible pressure transducer. We will select a transducer that will record water level readings between 0 and 15 feet bgs. The data logger is capable of collecting readings at intervals ranging from one reading per second to one reading per day and of storing 24,400 readings. We propose to set the data loggers to record readings once each hour. We propose to download information from the data loggers onto a laptop computer once each month, for a period of three months following well construction to assure the data loggers are operating properly. We will then download data from the loggers once per quarter for three additional quarters. The water level data will be translated into an electronic spreadsheet format and the data for each well will be plotted versus time to illustrate changes in water levels over time. We will summarize the groundwater data quarterly using a cumulative format. Quarterly Water Quality Sampline We propose to sample the water wells on a quarterly basis starting the first quarter after the wells have been developed. The following sampling protocol will be used to collect the water samples: • The groundwater depth in the monitoring well will be measured to calculate the number of well volumes required for purging. • The wells will be purged using a 12-volt pump while monitoring stabilization of groundwater parameters (temperature, pH and electrical conductivity). The pump will be decontaminated between each well sampling. • We will collect filtered and non-filtered groundwater samples to allow for assessment of potential aquifer matrix effects on groundwater chemistry. • Non-filtered groundwater samples will be collected using a disposable polyethylene bailer for each monitoring well and decanted into pre-cleaned laboratory sample containers. • Filtered groundwater samples will be collected using a disposable polyethylene pressurized bailer. The collected sample will then be passed through a 0.45 micron filter in the field and decanted into pre-cleaned laboratory sample containers. • All samples will be placed in an ice-cooled chest for transport under a documented chain of custody to the appropriate analytical testing facility. The water quality samples will be submitted for the analysis at Sequoia Analytical in Sacramento, California. Samples will be analyzed for a suite of general minerals and inorganic chemicals.