Of 68 such overflows from manholes or residences between 2004 and 2010, U.S. District Judge Edward Chen determined in a May 23 summary judgment that 21 qualify as violations of the federal Clean Water Act, including nine in the Atherton Channel, six in San Francisquito Creek, three in Corte Madera Creek and one in Los Trancos Creek.
Baykeeper's suit cites 162 overflows, of which 94 were less than 100 gallons. As for the other 47 100-gallon-plus incidents, the judge said he needs more information, which Baykeeper plans to provide, Executive Director Deb Self in an interview.
A trial on these unresolved spills, and a decision on penalties for all of the spills, is set for February or March of 2012, said West Bay's attorney in this case, Anthony Condotti of the Santa Cruz firm Atchison, Barisone, Condotti & Kovacevich.
West Bay looks good by comparison with the tanker that spilled 60,000 gallons of fuel oil after running into the Bay Bridge in November 2007, whereas the district spilled 45,000 gallons over six years, most of which was recovered before it reached the Bay, Mr. Condotti said.
If assessed the maximum penalty, the district will be out $975,000 for the 21 spills just resolved and possibly another $1.7 million for the other 47, he said.
Baykeeper has offered to settle, with any payout likely going to the Rose Foundation in support of a local environmental project, Ms. Self said.
Baykeeper, Mr. Condotti said, is employing a "novel" theory: if sewage escapes through a manhole cover and the district's clean-up leaves behind even "a single molecule" that could later travel to the Bay, that is reason enough for sanctions.
"Baykeeper is essentially seeking to hold the district liable for every spill when the vast majority are fully controlled," he said. The pollution levels are not even detectable let alone a cause of environmental harm, Mr. Condotti said, adding: "That's the heart of this case."
Ms. Self disagreed. "We showed and the judge agreed that 36,670 gallons of raw sewage contaminated creeks, sloughs and the Bay," she said. "That's not one molecule and certainly causes environmental harm."
"Thirty-five years of Clean Water Act jurisprudence says you can't discharge sewage into creeks. There's nothing novel about that idea," she added. "Now that West Bay's liability has been established by the court, it's not a matter of whether they are going to fix their whole crumbling system, but when."
Baykeeper settled similar cases with a Burlingame sanitary district and four nearby jurisdictions. Mr. Condotti acknowledged that history but noted that the district faces a large payout of ratepayer dollars either way: to Baykeepers' "pet charity" or in court.
Baykeeper has taken to overseeing water quality, Ms. Self said, because the regional water quality control board "is not able to enforce" the Clean Water Act. The board could not be reached for comment.
Sanitary districts must report all sewage spills to the state, which is how Baykeeper found the basis for this complaint.
"Ours are really tiny little spills, 100 gallons or less," West Bay District Manager Phil Scott told the Almanac. "We usually catch them before they affect anything."
The West Bay Sanitary District dates from 1902 and maintains 207 miles of pipe, much of it the same age as its neighborhoods, Mr. Scott said.
Eighty percent of the district's spills were due to tree roots intruding into pipes, Mr. Scott said. "The challenge is to try to maintain our lines and replace our lines without interfering with all the trees."
Phone calls and staff observations trigger many maintenance calls, he said. For several years the district's been using remote-control cameras to check flow conditions, and videos exist for about 90 percent of the system, he said.
When an incident involving a manhole cover occurs near a creek, the cover is often fitted with a robotic phone that calls authorities when it senses rising water, Mr. Scott said.
"We are doing the right thing," he said. "The effect is absolutely positive."