Reasons to Monitor and Sample Groundwater
According to the Groundwater Protection Council “The quality of groundwater can affect not only our health, but also society and the economy. Groundwater contamination can adversely affect property values, the image of a community, economic development and the overall quality of life we all share.” Contaminated groundwater can migrate off site, affecting nearby domestic water supply wells. Liability for these impacts lies with the owner of property from which the contamination originates.
Protecting Groundwater, Safeguarding Ecosystems
The quality of groundwater doesn’t exclusively affect human health, but other biota in the environment as well. Through monitoring well installation and sampling we are able to map the groundwater migration pathways and monitor the natural attenuation of contaminants. Often times, groundwater flows towards surface water sources such as rivers, creeks or lakes. If groundwater is contaminated, these harmful chemicals and compounds will often find their way back into these bodies of water, posing a detrimental threat to the wildlife that call those waters home.
Monitoring Well
Installation and Sampling Process
State-Licensed Drilling and Well Installation
Puget’s state-licensed drilling team advances borings using specialized truck-mounted, direct-push equipment and lines the borings with 1-inch-diameter polyvinyl chloride slotted piping and blank casing. The annular space of each boring is backfilled with washed silica sand from total depth to approximately 2 feet above the screened interval and sealed near the surface with bentonite. The wells are then completed at the surface with monuments set in concrete, and fitted with water-tight caps.
Periodic Groundwater Sampling
Groundwater samples are then periodically collected from the newly-constructed wells, as well as groundwater and well-head elevation levels to calculate the groundwater flow direction and magnitude.
Groundwater samples are collected using EPA approved low-flow purging and sampling techniques using a peristaltic pump with dedicated tubing. Field measurements including depth to water, pH, specific conductivity, temperature, oxidation-reduction potential and dissolved oxygen are also recorded at this time.
Groundwater Sampling Protocols and Laboratory Analysis
As with soil, groundwater samples are collected using laboratory-supplied containers and placed into an iced cooler pending transport to the analytical laboratory. All samples are examined by Puget’s Washington State-licensed geologist before laboratory testing.
