Following is formal notice from Public Works Department Director Paul Cranmer notifying the City Council of the detection of per-and polyfluoroalkyl substances (PFAS), known casually as forever chemicals, in the drinking water at our Orange Grove Well Site next to Fire Station 107. The amount detected is below the level of needing to shut down the well, but it meets the level of needing
to notify the governing body of the occurrence. We are looking into options for adding treatment to this well and possibly the two lower City wells that pump into this one. As we have told you over the past few years, adding treatment to our system is becoming increasingly important to our ability to provide local water to our residents. We will surely be
discussing this during the budget season as well as during the water rate discussions later this year. In the meantime, we will continue testing and monitoring the situation and will shut down the well if levels continue to rise.
FROM: Paul Cranmer, Public Works Services Direc
SUBJECT: Detection of Perfluorohexane sulfonate in Orange Grove Reservoirs Blend
Background
Pursuant to Section 116455 of the California Health and Safety Code, the City is
required to notify its governing body that the subject drinking water well has exceeded
the Notification Level for Perfluorohexane Sulfonate ("PHx"), an unregulated
fluorinated organic compound.
PHxS is a member of a large class of chemicals known as per- and polyfluoroalkyl
substances (PFAS"). PFHxS i s a six-carbon fluorocarbon with a functional group that
acts as an anionic surfactant that can be used in numerous commercial products to offer
water and stain-repellent properties and in fire-fighting foams. It does not occur naturally,
and its presence in the environment is due to anthropogenic activity. Due to its
garain mi he l stile anund perso i, the fi o n and in logical
PFHxS i s part of the Unregulated Contaminant Monitoring Rule ("UCMR") by the
California State Water Resources Control Board Department of Drinking Water ("DDW*)
and no Maximum Contaminant Level ("MCL") has been established. However, the DDW
has established a Notification Level, or a health-based advisory level, for chemicals in
drinking water that lack an MCL. The current Notification Level for PHxS is 3 parts per
trillion (ppt). DDW has also established a response level of 20 ppt.
To put this into perspective, 1 part per trillion is equivalent to a single drop of water in 20
Olympic size swimming pools. For Orange Grove Blend it would be 4.8 drops in 20
Olympic-size pools. Studies indicate that long term exposure to PHxS over certain
levels may result in adverse health effects.
Drinking Water Samples
PHS tom Orange Grove elem V. Stre folong resug to colect water samples for
Orange Grove Reservoirs Blend
• 4.8 ng/l sampled on 11/27/2023
Future Monitoring
Orange Grove Reservoirs Blend is the entry point into the water system from the
combined influence of the Orange Grove wells and Zone 4 wells. This entry point wil
continue to operate as allowed by DDW and the City will continue to conduct required
monitoring at this location. If levels of PHxS continue to increase, it may become
necessary to construct a water treatment facility to reduce the level of contaminant in the
water or remove the well from service. The purpose of this memo is to comply with DDW
regulations that include notification of the City Council. The regulations do not require
that the well be taken out of service at this time. If you have any questions or concerns,
please do not hesitate to contact me.