Winter storms test East Bay’s progress on leaky sewage lines

Apr 10, 2023

It's been a tricky time for sewage in the urban East Bay. This winter's pounding rains tested the capacity of the largely underground wastewater system.

Add to this what some wastewater experts believe is a clogged-pipe pandemic side-effect from an uptick in wipes in the system, leading to sewage leaks. A ubiquitous COVID-19 sanitation tool, pre-moistened paper wipes aren't meant to be flushed down toilets, similar to diapers and feminine hygiene products. In particular, Oakland has identified wipes as a culprit in several sewage overflows in the past few years, aligned with COVID-19.

But heavy rain, tree roots, and kitchen grease, known in sewage lingo as FOG —fats, oils and grease — are still the main culprits challenging East Bay communities’ ability to contain their sewage as it flows from building to treatment plant.

Water in rain-saturated soil seeps into sewage pipes through cracks and breaks. The heavier the rain, the heavier the volumes of groundwater in pipes resulting in overflows into streets and gutters. Clogs make things worse, leading to cracks and breaks.

As well, some people illegally connect roof drains or basement sump pumps to sewage lines, adding to sewage pipe rainy day water volumes.

Sewage also escapes through broken pipes, spreading through soil and groundwater. Gravity usually transports it downhill into watersheds or the bay.

In sewage parlance, these pipe stresses are called I & I — infiltration, from groundwater, and storm water inflow, from illegal connections, both recognized as major causes of system failure.

This was strikingly evident on the second wettest day in the Bay Area since rain levels were first recorded in 1849: Dec. 31, 2022. Three EMBUD maintenance holes overflowed on this unusually stormy day, including one in Berkeley, at Page and Second streets.

The other two, both also operated by EBMUD, were in Albany along the Eastshore Highway and in Alameda at Broadway and Clement avenues.

During the same intense rain, the utility also released 4.7 million gallons of partially treated wastewater into the bay from overflow facilities, called wet weather facilities, in Oakland and Alameda into the Oakland Estuary — a step taken to relieve pressure when systems are overloaded.

These releases are likely violations of state and federal water laws, and EBMUD will get cited, sources say, but this is a process that can take years.

In addition to EBMUD sewage infrastructure, cities own and maintain their own systems. And this winter's precipitation challenged them, too. Oakland in particular, data shows, was hard hit.

EBMUD's wastewater system is essentially a massive underground funnel. Sewage generated in buildings travels through private pipes, called sewage laterals, to city pipes, usually under streets, to EBMUD's massive interceptor pipes running along the SF Bay shoreline, and finally to its treatment plant near the Bay Bridge terminal.

Pumps along the way help move flows. Maintenance holes allow workers access to pipes.

On that wet Dec. 31, 2022, Oakland reported eight significant (defined as reaching the surface and/or never being contained) sewage overflows from its pipes. The city of Berkeley fared better, reporting no sewage overflows on its system that day. Only the EBMUD maintenance hole in West Berkeley overflowed.

Sewage spills or leaks (usually called "SSOs" for sanitary sewage overflows) on public lands must be reported to the California Water Resources Control Board, which shares the information on an online public map.

Reporting sewage leaks on private property is optional. But when this data is reported, it's also mapped.

We reached out to the city of Oakland several times, starting a couple of weeks ago, for more information and haven't heard back.

For many East Bay sewage watchers, any leakage today might have been much worse. That's because EBMUD and its wastewater customers are part way through a court-ordered sewage improvement plan, after decades of polluting the bay.

The plan, a 2014 legal settlement outlined in a consent decree, requires EBMUD, the cities of Berkeley, Oakland, Albany, Alameda, Emeryville, Piedmont, and the communities of the Stege Sanitary District (El Cerrito, part of Richmond and the unincorporated community of Kensington) to make billions of dollars of sewage infrastructure improvements over a 22-year time period, ending in 2036.

The cities are referred to as satellites in the decree.

Reached after decades of legal actions around chronic sewage violations, the settlement was the result of a lawsuit by two environmental nonprofits, Baykeeper and Our Children's Earth, joined by the Environmental Protection Agency (EPA), the U.S. Department of Justice (DOJ), the California Water Control Board and the Bay Area Regional Water Quality Control Board. Prior legal mandates were folded into the decree.

The utility and satellites were also fined.

The work is focused on stopping EBMUD from illegally releasing partially treated sewage into the bay from its three wet-weather facilities, two in Oakland and one in El Cerrito.

These facilities are basically wastewater storage tanks for excess flows during hard rains equipped with pumps for quick release into the bay, as needed. This sewage wastewater is disinfected, or partially treated before it's released.

Built in the 1990s, the facilities were intended to help mitigate system stress during extreme rainfall.

But the concept backfired after some misunderstandings or regulatory rethinking. In 2004, the EPA reversed its earlier determination, saying the partially treated water was against federal water law.

Though the wet weather facility mix is heavily stormwater versus raw sewage, even with disinfecting it can still be unhealthy to humans and animals, including marine life.

"EBMUD won awards for the wet weather facilities. Ironically, [EBMUD] got federal funding and ironically, [the federal government] decided they were in violation of the Clean Water Act," said Eileen White, administrator of the Bay Area Regional Water Quality Board, the local branch of the state water board, a regulatory agency that enforces federal and state clean water laws.

Under the consent decree, the facilities must gradually stop operating by 2036, allowing time for the completion of other required sewage system work.

"The whole goal is to minimize the operating of the wet weather facilities over time by fixing the aging sewer pipes," White said.

The consent work covers inspections, repairs, replacements, clean up and ongoing maintenance, with required benchmarks, deadlines and reporting.

Costing cumulatively hundreds of millions of dollars for EBMUD and the satellites, most of the work will be paid for by ratepayers and taxpayers.

The plan follows an asset management approach, a multi-year plan to fix and maintain all parts of a complex sewage system, from the smallest pipes to the most massive, for overall long-term benefit. In this case, stopping polluting releases from EBMUD's wet weather facilities requires a smooth-running leak-free sewage system all the way from toilet to the treatment plant.

The consent decree takes the view of a collective problem, requiring a collective fix.

Now, almost midway into the decree, work is on schedule, said John Senn, EPA spokesperson.

Water in rain-saturated soil seeps into sewage pipes through cracks and breaks. The heavier the rain, the heavier the volumes of groundwater in pipes resulting in overflows into streets and gutters. Clogs make things worse, leading to cracks and breaks.

EBMUD and the satellites have met required benchmarks to date, with a midway review last year, he said.

"The EBMUD consent decree is a twenty-two-year-long agreement, so we recognize improvements to the sanitary sewers is a gradual process that will take time to implement. We are a little more than half way through the agreement. The cities and EBMUD for the most part have been in compliance with the agreement," Senn said.

In total, EBMUD and communities under the decree were told to rehab nearly 200 miles of sewer system and certify as leak-free 50,000 private sewer laterals. "The parties have spent approximately $300 million on sewer rehabilitation and have completed over a third of the required work," Senn said.

"In 2022, we had the first mid-course check-in of the consent decree, and modeling demonstrated that the work under the consent decree is on track. There is still much work to be done before 2036 and the termination of the consent decree."

Each satellite and EBMUD have individualized work requirements, phased from 2014 until 2035. Much of this work is a tighter-ship enforced layer added on top of sewer system improvements the cities and the utility were already taking.

Old sewage infrastructure throughout the urban East Bay has been a costly, whack-a-mole public works trouble area, with cities trying to stay ahead on repairs.

Old sewage infrastructure throughout the urban East Bay has been a costly, whack-a-mole public works trouble area, with cities trying to stay ahead on repairs.

In Berkeley, most of the city's sewage system has been replaced to meet the consent decree, said Matthai Chakko, spokesperson.

The city, population roughly 117,000, has about 254 miles of public sewage lines and seven pump stations. "We have steadily upgraded over 90 percent of City sewer lines over the past 35 years to prevent or minimize infiltration of stormwater into the sewer lines," Chakko said.

Oakland, population about 433,000, has around 934 miles of sewage pipeline, and 11 pump stations. According to city reports, Oakland had rehabilitated 96.4 miles of its sewer main lines from 2014 to the end of the 2022 fiscal year, exceeding the consent decree requirements. By the end of the decree, the entire system is supposed to be shipshape.

The satellites are only one part of the decree work, the feeders into the big machinery of EBMUD. The utility is also required to upgrade its infrastructure, from pumping mechanisms to interceptor pipes to identifying weak spots that allow storm and ground water to enter pipes meant for sewage.

The utility is also required to develop an urban runoff diversion system from an Alameda County stormwater pump at Ettie Street in Oakland.

On track, said Andrea Pook, utility spokesperson.

"EBMUD has done extensive CCTV to identify the condition of the interceptor pipes, so we can prioritize based on risk and set deadlines/schedules for the work. … In the next 5 years there are several projects – 4-5 segments – planned for improvements," Pook said.

"EBMUD has made emergency repairs in some cases, and has bumped up the timeline on others as we reprioritize based on data from the inspections."

Even with decree work on track, sewage leaks and releases are still happening at all points in the system, private, city and EBMUD infrastructure — primarily in heavy rains.

For example, from July 1, 2019, to June 30, 2021, Oakland had 48 sewage overflows and was fined $151,200; Berkeley had four, with a fine of $800; Alameda had seven, and was fined $5,400, and the Stege Sanitary District had one, with a fine of $200, according to a September regional water control board report.

EMBUD was fined $50,000 for two sewage overflows, and $29,000 for pollution violations from releases at its Point Isabel wet weather facility associated with a power outage during a storm in October 2021.

Prior years in the consent decree have also seen sewage leaks, and related EPA fines.

In its required 2021 progress report on the consent decree, Oakland acknowledges challenges.

"The impact of COVID-19 on the City's sanitary sewer rehabilitation design and construction work has been significant during FY20-21. The City experienced considerable delays and interruptions to multiple phases of project development, contract bid/award, and construction," the report said. Some projects were postponed.

As for those prolific wipes, the city report said:

"Disposal of non-dispersible wipes into the collection system — which increased substantially at the onset of the regional shelter-at-home order — continued to impact efforts to reduce the total number of [sewage] overflows."

Consent decree progress reports for last year aren't yet available.

If the plan goes as hoped, violations will drop year by year, with completed repairs. There are signs this is happening.

"Without the improvements made under the consent decree, it is likely there would have been even more raw sewage spilled." — Nicole Sasaki, Baykeeper attorney

According to a 2020 EBMUD progress report, discharges from wet weather facilities dropped by 19% overall since the decree was enacted in 2014, with the greatest reductions at the Oakland sites, Oakport Street (25% drop) and San Antonio Creek, on 5th Avenue (26% drop).

"We’re seeing the benefits of the consent decree," said White, administrator of the regional water board. "I would say had they not done all the improvements since 2014, we would have seen significantly more sanitary sewage overflows."

Said Pook, of EBMUD: "The biggest thing that we are excited about is that by achieving interim compliance, we’ve demonstrated that the ‘asset management’ approach for addressing infrastructure challenges is effective."

Nicole Sasaki, the staff attorney for Baykeeper, agrees, but more cautiously.

"Without the improvements made under the consent decree, it is likely there would have been even more raw sewage spilled into our streets, creeks, and SF Bay [this winter]," Sasaki said. "We would be in a much worse place than we are now."

But, she said, with some climate change models predicting more precipitation-heavy Bay Area storms, more system upgrades may be needed.

"Even if EBMUD and the satellites continue to stick with their [pipe testing and repair] plan, they will still not be able to handle the more extreme weather events in our future. We will continue to have large sewage spills into SF Bay because our systems are just not built to handle these large storms," Sasaki said, when asked about the potential effects of climate change on the consent decree approach.

The impact of this winter's rains hasn't yet been factored into the latest consent decree review, she said. The required 2022 review last year was based on data from before this winter's torrential downpour.

"With climate change California is experiencing climate whiplash, periods of extreme drought and periods of extreme rain," Sasaki said. "During the existing monitoring under the consent decree, most of the time we were in extreme drought, with a couple of wet years."

She asked: "How do we design these models to be long enough to collect enough data to reflect these extreme highs and lows, which is very difficult from an engineering and planning perspective. … How does climate change impact how we decide whether or not we have enough data to produce an accurate model."

Senn, of the EPA, said consent decree models adjust to changing weather.

"Climate change is not specifically mentioned in the Consent Decree but remains a top concern of EPA," he said.

"The progress of the consent decree is measured by monitoring actual storm events and using that data to model an expected event. These heavy rains help provide more data to understand how the system performs, how well that matches the model of the system, and how it will be used to calibrate the model for the future, Senn said.

"In 2022, we had the first mid-course check-in of the consent decree, and modeling demonstrated that the work under the consent decree is on track. There is still much work to be done before 2036 and the termination of the consent decree."

White is optimistic. "With each year that passes we’ll be better prepared to deal with these atmospheric rivers," she said.

What will be allowed from the wet water facilities after the end of the consent decree isn't completely clear.

"The consent decree is phasing out the frequent use of wet weather facilities during the average year. The wet weather facilities will remain in place for storage, and they may be used to partially treat and discharge sewage in larger, less frequent rainfall events," said Senn, of the EPA.

Last month, a kayaker paddling along the Berkeley shoreline saw what looked like raw sewage dripping from under Skates on the Bay restaurant, reporting it to the nonprofit Baykeeper's pollution hotline. The organization notified the city, which confirmed it was a sewage leak. The restaurant fixed it right away.

Without the observant, and perhaps grossed out, kayaker, this sewage drip may have gone on much longer.

A leaky pipe, first noticed by an alert paddler, was plugged on April 13. It's not clear how long raw sewage had been flowing into the bay.

And this points to a vulnerability in the sewage consent decree's ability to succeed: This sewage leak was on private property.

Under the consent decree, the cities or satellites are required to fix their infrastructure, with annual goals for a complete overhaul.

But fixing private sewage pipes is much trickier. Private property owners can't be forced to inspect or repair ailing sewage pipes in any of the areas covered by the consent decree. For many miles of private lateral, no one knows their condition.

To attempt to address this, the consent decree requires measures to address private sewage laterals including requiring certified leakfree pipes before any property sale. Some cities already had similar regulations on the books, but the consent forced uniformity.

All satellites but Berkeley joined in one private lateral public program. Berkeley opted to operate its own, similar effort, now part of the municipal code.

Under these regulations, property owners in the satellite communities including Oakland must repair or replace their private sewage laterals whenever a property is sold or changes ownership; whenever changing the size of a water meter; whenever they replace a water meter; before getting a building permit for major work; or when the city discovers a sewage leak or issue.

All of these apply to Berkeley properties except for the water meter change. Berkeley also points out that inspection and certification are required whenever anyone wants to replace their private sewer lateral.

The city of Berkeley has certified 13,518 clear and operating sewage laterals since it began doing this in 2006, of 31,600 total, said Chakko, city spokesperson. Of these, 5,862 were issued since the 2014 consent decree became effective. (We are trying to get comparable data from Oakland, but haven't heard back from the city.)

Sasaki from Baykeeper said private laterals are still a weak spot.

13,518 of Berkeley's 31,600 sewage laterals have been certified as clear and operating since 2006

"In practice, this approach isn't resulting in as many repaired private laterals as hoped for," she said. Cost is a deterrent.

"A better approach," she said, "might be to establish a private lateral repair reimbursement program, incentivizing all home or business owners to repair and replace their private laterals with the promise of government reimbursement to help defray the cost."

For information on getting your private lateral inspected and certified as leakfree, check the East Bay Private Sewer Lateral website, or the city of Berkeley's sewer lateral program.

One area of agreement among those working on the consent decree (the satellites, environmental organizations, regulatory agencies) is that sewage systems, like any building or infrastructure, need ongoing maintenance to stay in shape.

The consent will work only as long as everyone is doing their part.

"Note that sewer pipes, which are currently leak-free, may, too, begin to leak at some future point, due to age, earthquake, or other causes," Pook said. "Nothing lasts forever, and infrastructure renewal is a constant need."

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Freelancer Catherine "Kate" Rauch has been contributing to Berkeleyside for several years. Her work as a journalist has encompassed everything from 10 years as a daily news reporter for the East Bay Times,... More by Kate Darby Rauch