Resident sues Folsom over pinhole leaks in copper pipes, says city knew water was corrosive

A Folsom resident is suing the city of Folsom for damages caused by pinhole leaks in copper water pipes, an issue that has plagued city officials and residents for nearly two years.

The lawsuit, which received class-action status in April, accuses the city of negligence and breach of contract, among other things, and is seeking unspecified compensation for damages for all residents who were affected.

The city of Folsom declined to comment, a spokesperson said, saying the city does not comment on litigation matters.

The lead plaintiff, Harold Malmquist, filed the suit after experiencing two leaks in the cold water pipes in his house, causing $79,000 in repairs. The water supplied by the city’s water treatment plant is the culprit behind the leaks, the lawsuit alleges.

“The city began experiencing widespread pinhole leaks in copper piping at residential and business locations throughout the distribution system in or about July 2020,” the lawsuit said. “Aggressive, corrosive, and substandard water supplied by the city’s water treatment plant caused the pinhole leaks thereby damaging properties in the city that are plumbed with copper piping.”

Since June 2020, the city has received more than 2,000 reports of pinhole leaks.

The lawsuit alleges the city had knowledge that the water it supplied to residential pipes was corrosive and the source of the pinhole leaks.

“Despite longstanding knowledge of the cause of plaintiff’s and class members’ potential damages due to high pH and low alkalinity levels, among other things, the city continued to misrepresent to plaintiff and the class members that its water supply is not defective or harmful to property, and damages incurred by plaintiff and the class members was not the result of any action on the part of the city,” the lawsuit said.

The city began investigating the pinhole leaks in July 2020 and hired two third-party consulting firms to research the issue and make recommendations to the city how to mitigate the leaks.

One report, prepared by Black and Veatch, a Rancho Cordova-based consulting company, said it was the city’s pure water that was at the heart of the problem.

“The city has produced a high-quality potable water that under most circumstances provided the optimal corrosion control treatment as demonstrated by historical compliance with the (EPA’s Lead and Copper Rule),” a city report said. “However, the purity of this water source resulted in a rare set of conditions that can contribute to pitting conditions in copper pipe.”

Drawing its water from the snowmelt collected from the Sierra Nevada, Folsom has a uniquely pure water source. So pure, in fact, that it is devoid of many minerals that are important to maintain a neutral pH while it is pumped through copper pipes, the report said.

The lack of minerals can cause the water to act “aggressively” toward metallic pipes, according to the report prepared by Black and Veatch. The water tries to pull minerals from its surroundings to neutralize, but damages the pipes in the process.

To help slow the pitting, the city has added orthophosphate to the water treatment, an EPA-approved chemical that is added to water systems to help delay the corrosion of metal pipes. It is safe to drink.

“The use of orthophosphate has been shown to inhibit pitting in aggressive waters by hindering pit initiation ... and it can help to slow or even mitigate pit propagation on pits that are already initiated,” the report said.

This story was originally published October 11, 2021 at 11:52 AM.