A builder faces possible six-figure fines in connection with a massive spill of silt-laden, construction runoff water into a Gilroy creek near Christmas Hill Park from the Glen Loma Ranch subdivision under construction on the west side of town.
The California Regional Water Quality Control Board cited CalAtlanic Homes, formerly Standard Pacific Homes, on June 14 for violations of its construction permit in connection with the retention pond breach near Las Animas School in South Gilroy.
The failure sent an estimated 500,000 gallons into Uvas Creek, home to protected steelhead trout and other species of fish and wildlife.
The breach was witnessed, photographed and filmed by a nearby resident, who reported it to city officials, who in turn alerted the state water board.
The breach was first detected on Feb. 20 and was reported by the city to the state on March 1. But it continued after it was discovered because equipment brought in by the developer to stem the flow was inadequate, officials said.
As a result, CalAtlantic was granted an extension to fix the problem as ordered by the state. The retention basin as since dried up.
“It’s very rare on this scale,” said David Innis of the water quality board. “To have it fail like that, I’ve never heard of it before,” he said.
Gilroy public works director Rick Smelser and inspector David Manigold worked on the case and reported it to the state.
They said noise from the gushing water was so loud it attracted attention of a nearby resident, who documented the incident and called the city.
Although no decision has yet been made regarding whether CalAtlantic will be punished, the board can impose fines of up to $10,000 a day for violations. If the California attorney general takes action, the builder could be hit with fines of up to $25,000 a day, according to the citation letter.
In addition, other state and federal agencies that share jurisdiction of the creek have been notified and could investigate and take their own enforcement action, officials said.
They include the California Department of Fish and Wildlife and the National Oceanographic and Atmospheric Administration’s fisheries division. The latter has protective responsibility for ocean-going steelhead trout that spawn in the creek and its tributaries in the Pajaro River watershed.
Other agencies that have been notified and could be drawn into the probe are the Santa Clara County district attorney and the Santa Clara County Habitat Agency.
Irvine-based CalAtlantic Homes did not respond to requests for comment.
The one-acre retention pond, or basin, is designed to operate during and after the construction phase of four separate developments involving 274 new homes in the Glen Loma Ranch project, the city’s largest subdivision.
The pond is a repository for captured construction water runoff from new streets in the development. When completed, Glen Loma Ranch will occupy 309 acres along the east side of Santa Teresa Boulevard, roughly from just north of Solorsano Middle School south nearly to the Thomas Road intersection.
The runoff collection system is meant to prevent unfiltered runoff that might contain motor oil and other pollutants from entering the creek and the larger Pajaro River watershed. The Pajaro empties into the Monterey Bay.
Runoff flows to the pond where it is percolated through special soil that removes fine silt and other pollutants that can clog the creek and kill fish and other wildlife.
After passing through the filtering layer, the water is collected via a latticework of small, underground pipes that convey it to a 3-foot diameter pipe that discharges the filtered runoff directly into the creek.
However, the latticework had not yet been installed and, for unknown reasons, the 3-foot pipe worked itself loose from the pond bottom, floated upwards and ruptured, according to Innis of the water quality board.
He said the retention basin has since dried up, but that the breach deposited a great deal of slit in the creek before the flow stopped.
Innis added that silt particles become suspended in the creek water making it difficult for fish to breath and see their prey.
City officials and Innis suggested that initial indications are that the failure could not have been foreseen and might have been, in effect, an unavoidable accident due to the pond’s design.
The state water quality control board’s notice of violation was sent to Ron Buck at CalAtlantic’s Pleasanton office. It explains the developer’s liability and corrective measures to be taken. It notes that the discharge of “turbid, sediment laden water lasted 15 days and “deposited at least 15 cubic yards of very fine sediment in Uvas Creek.”
The notice goes on to say that, “City of Gilroy inspectors visually verified the Mataro Basin piping was damaged and much of the sediment laden water drained from the basin. City inspectors stated the unauthorized discharge was initially reported by local citizens who observed and photographed the discharge before 9:00 a.m. on February 20, 2016 and reported the observation to the City of Gilroy Public Works and Fire Marshal’s Office.
