Manteca is preparing to spend $14.3 million to make sure ground water from five wells meet higher standards implemented by the state of California when it comes to acceptable levels of 1,2,3-Trichloroprane — a Shell Oil and Dow Chemical product used in certain soil fumigants area farmers used between 1950 and 1980 .
The City Council when they meet tonight is expected to award a contract to C. Overaa & Co. to install state-of-the-art granular activated treatment facilities for the impacted wells. The council meets at 7 o’clock at the Civic Center, 1001 W. Center St.
Prior to the California State Water Resources Control Board raising the standard on July 18, 2017 to 5 parts per trillion, all city wells were in compliance. The state ordered the city on March 22, 2018 to meet the new standards on the wells in question. They have until March 22, 2021 to comply to the new standards.
The current levels are not considered an imminent threat to health. If they had been, the state would have ordered the wells to be shut down immediately. The new state standards are part of an ongoing effort by California to continue increasing drinking water standards.
The City Council has been meeting in closed session of and on over the past year to discuss litigation/possible litigation with Dow Chemical and Shell Oil. It is not clear what the status of litigation is, if any, at this time.
Given the $14.3 million cost to remove TCP that is a 100 percent manmade chemical that was an impurity in certain soil fumigants sold to farmers it is likely if there is some course of action to recover part or all the costs the city is likely to pursue it.
The work is being undertaken in conjunction with the creation of a central arsenic treatment facility for the wells similar to one that was built on Moffat Boulevard several years ago. The federal government has established higher standards for arsenic that naturally occurs in ground water although it can be introduced from other sources.
The city is shifting money from other water-system related projects to pay for the work.
In regards to arsenic concerns, the following information is posted on the city’s website:
“Our water system recently failed a drinking water standard. Although this is not an emergency, as our customers, you have a right to know what happened, what you should do, and what we are doing to correct this situation. We routinely monitor for the presence of drinking water contaminants. Recent testing results show that nine wells in our system exceed the standard, or maximum contaminant level (MCL), for Arsenic. The Federal standard for Arsenic is 10 ug/L. The annual average of the nine wells that are out of compliance is 13.7 ug/L. Compliance with the arsenic MCL is based on the average concentration of four consecutive quarterly samples (or an annual average) for each well, unless fewer samples would cause the running annual average to be exceeded.
“You do not need to use an alternative (such as bottled) water supply. However, if you have specific health concerns, consult your doctor.
“This is not an immediate risk. If it had been, you would have been notified immediately. However, some people who drink water containing arsenic in excess of the MCL over many years may experience skin damage or circulatory system problems, and may have an increased risk of getting cancer.
“The Environmental Protection Agency (EPA) recently reduced the Arsenic MCL from 50 ug/L down to 10 ug/L. In accordance with this reduction, the City of Manteca collected samples from all of its wells and to date nine wells contain water with Arsenic levels above the MCL.
“The City of Manteca is currently installing filters to remove arsenic from wells with arsenic levels above the Federal MCL of 10 ug/L. In the meantime, the City is maximizing water production from sources with low arsenic levels.”
To contact Dennis Wyatt, email dwyatt@mantecabulletin.com
