Lodi officials spent Tuesday morning learning about water and soil extraction wells that the city installed to deal with groundwater contamination. The council toured the two wells and treatment facility in the alley between Church, Pine, Oak and Pleasant streets as part of the meeting.
The equipment is the result of the city's monitoring and cleanup of PCE/TCE, two chemicals commonly used by dry cleaners and metal shops decades ago. The chemicals ended up in the soil, and after a long legal battle, the city reached a settlement with a variety of local business, including the Lodi News-Sentinel.
The city is required by the state to monitor the contamination and extract it from the central plume.
Councilman Larry Hansen stressed that the measures are because the city wants to preserve its water supply.
"I just want to stress that our water is clean, that it's safe, and that we are going through all of this to make sure it continues to be so," Hansen said.
The city installed the permanent wells and started operating them in March 2011. But before that, there was a pilot facility that also removed the chemicals. Between 2006 and 2011, the city removed 8,023 pounds of PCE/TCE from the ground, according to city staff.
The council discussed the different plumes of contamination and how it is moving deeper into the ground as it moves south. The city is continuously working with Central Valley Regional Water Quality Control Board on a strategy of how to deal with the contamination, Public Works Director Wally Sandelin said.
Lodi is treating the contamination two different ways. The first is soil vapor extraction that pulls the chemicals through the ground and into the treatment system. The vapor is run through carbon filters to remove the PCE/TCE and then the vapor is discharged into the air.
The second way is through extracting the groundwater and also running it through carbon filters. The city then has to dump the treated water in the sewer. The city has so far extracted, treated and then dumped 27 million gallons.
Lodi resident Ed Miller, who also is a member of Citizens in Action, the local Tea Party organization, said he wishes the state would allow the city to use the treated water.
"It's an incredible waste, especially because there is a limited supply of water in the Central Valley," Miller said.
Instead of extracting the water and then dumping it, Public Works Director Wally Sandelin said he is hoping the city will eventually be able to install equipment to remove the chemicals if it reaches one of the city's 28 well sites.
He said staff would prefer that over the current plan of using the extraction wells to remove the chemical, in part, because it is wasting groundwater that could be used once the chemical is removed. He said the city will continue discussing the issue with the state board.