Cancer-causing chemical found in soil at 4 sites in SLO. What’s being done about it?
Four sites in San Luis Obispo have potentially dangerous levels of soil contamination from a toxic chemical used by dry cleaning companies for decades, according to documents from the state and local regulators.
Tetrachloroethylene — known as perc or PCE for short — was used to effectively clean clothes and is considered a “likely human carcinogen” by the U.S. Environmental Protection Agency.
Decades after PCE was discovered to be leaching through the soil and into an underground aquifer the city of San Luis Obispo soon hopes to tap for drinking water, state agencies are planning to clean up the chemical contamination.
The California Department of Toxic Substances Control and Central Coast Regional Water Quality Control Board have identified four San Luis Obispo sites where PCE soil contamination is prominent in levels of up to about 865 times above the safe limit.
The most contaminated areas are under parking lots and adjacent to current and former dry cleaners, according to reports housed on the state agencies’ websites.
The agencies have taken soil and indoor air quality samples at those locations to determine whether the PCE pollution poses a health risk to those who frequent the areas.
However, San Luis Obispo is the only city in San Luis Obispo County where the state has conducted a comprehensive investigation into possible PCE soil and air pollution from dry cleaners, which can be found in most local communities.
What is dry cleaning chemical PCE?
Pollution from dry cleaners isn’t uncommon.
A 2006 state Air Resources Board report estimated that at least 82% of dry cleaners in California used PCE as a cleaning solvent. And a survey conducted by the State Coalition for Remediation for Dry Cleaners estimated that 75% of dry cleaning facilities in the United States have caused PCE contamination.
From the 1930s to late 1980s and 1990s, San Luis Obispo dry cleaning companies used PCE to clean clothing.
As laundry loads were moved from one machine to the other, some of the chemical fell to the ground or evaporated in fumes into the air. Operators also would dump the chemical down the drain after it had been used.
From there, PCE made its way into the soil beneath the dry cleaners’ buildings and parking lots. If the soil wasn’t clay, the chemical easily seeped into the groundwater aquifer.
The use of PCE has been phased out in California since 2007, and a total ban has been in place since Jan. 1, according to regulations by the California Air Resource Board.
After an investigation by the regional water board, San Luis Obispo’s groundwater source was found to be contaminated with PCE in the early 1990s.
At the time of that investigation, little was done to pinpoint the exact sources of the pollution in the aquifer or clean it up.
Two decades later, in 2011, the DTSC hired an environmental consulting firm, URS Corp., to conduct an investigation to pinpoint where the PCE contamination in the groundwater was coming from.
URS found 16 former or current dry cleaners in San Luis Obispo that could have PCE contamination, as well as 18 “other sites of interest,” according to its report sent to the DTSC.
After initial tests of the soil around those properties, the consulting company narrowed it down to four sites that had concerning amounts of the chemical within the soil.
The report suggested to DTSC that further evaluation was needed to fully grasp the extent of the soil pollution at the properties.
Reports: Toxic chemical found in soil at SLO sites
In 2012, investigators measured PCE at a level of 57,000 micrograms per cubic meter in the soil at Paul’s Dry Cleaners & Laundry in San Luis Obispo, according to a 2020 report prepared by Geosyntec consultants for the DTSC.
That’s more than 850 times the amount considered safe for humans.
Levels of PCE in the soil above 67 micrograms per cubic meter at businesses, and 15 micrograms per cubic meter at homes, are considered potentially unhealthy by the California Department of Public Health, and can possibly lead to the air within buildings on top of the contaminated soil being polluted.
Minuscule amounts of the contamination were detected in the air at Paul’s Dry Cleaners, according to the report.
The soil pollution at the business at 214 Higuera St. “may present an imminent and/or substantial endangerment to the public health,” according to a site remediation order issued by the DTSC in June.
The owners of Paul’s Dry Cleaners are required by the DTSC to clean up the pollution.
Cleanup has yet to begin and may initially cost Paul’s Dry Cleaners $35,000, general manager Rod Morabito said.
That’s substantial expense for his family’s business, which saw revenue drop since the start of the COVID-19 pandemic, he said.
Morabito said he feels it’s his duty to the health of the public and the environment to clean up the PCE pollution.
“It’s painful, but you gotta do it,” Morabito told The Tribune.
At the former home of Mission Laundry & Dry Cleaner at 331 Pacific St. in San Luis Obispo, investigators in 2017 found levels of PCE up to 58,000 micrograms per cubic meter in the soil, according to data from the regional water board.
That’s more than 865 times above safe levels.
PCE was likely used at the property in the 1950s and 1960s, according to a 1992 water board report.
The regional water board has requested the owner of the property to clean up the site.
However, the cleanup is expensive, so the owner is hoping for a grant from the state to fund at least part of it, according to Greg Bishop, a senior engineering geologist and site cleanup manager for the Central Coast water board.
At 385 Higuera St., which historical documents show was occupied by dry cleaners from 1949 through the late 1970s, investigators measured PCE pollution of up to 34,490 micrograms per cubic meter in the nearby soil, according to a 2015 report by engineering company URS.
“No (remediation) order was issued to Spotless Dry Cleaners as findings revealed that no dry cleaning operations occurred at this site,” DTSC public information officer Alysa Pakkidis wrote in an email to The Tribune.
And at 1085 Higuera St., where American Riviera Bank is a tenant, investigators found 33,900 micrograms per cubic meter of PCE in the soil, according to a September report by consulting company Haro Environmental.
Dry cleaners operated on the property from 1962 through 1983.
Similar to the order at Paul’s Dry Cleaners, DTSC issued a remediation order to the owner of that property in July because of the potential for the PCE pollution to seep through the soil and sewer lines into the air at the bank or surrounding businesses.
However, that remediation order was overruled when the regional water board took over management of the property’s pollution.
The pollution at the American Riviera Bank site is set to be cleaned up over the next few years at an estimated cost of $400,000 to $500,000, according to Phil Goalwin, a consultant hired by the property owner to help with the site’s monitoring and remediation.
In the meantime, indoor air pollution at the bank is being mitigated with air filters to prevent any health risks, according to Bishop.
Each of these four San Luis Obispo sites has sewer lines where PCE could have been dumped, Bishop said.
The DTSC and regional water board have done some investigation along the sewer lines around the four properties to see if the pollution may have leaked in other areas of the city, he said, but such work is tricky.
“It’s difficult to know how far downstream to keep looking,” he said. “There may be a crack at one spot, and then 50 feet down another crack. If we stop seeing impacts at some point, we conclude it probably didn’t reach that far.”
Does contamination exist outside of SLO?
The Central Coast Regional Water Quality Control Board has not investigated other current or former dry cleaners outside of the county seat to determine if they have caused PCE pollution in the soil and air, Bishop said, because other sites have not been put on its radar.
Oftentimes, the regional water board is made aware of polluted sites when there is a real estate transaction such as the sale of a site followed by new construction.
When Firestone Walker Brewing Co. acquired an old dry cleaner building in Paso Robles that it wanted to demolish to expand its facilities, Bishop said, the craft brewery had to clean up the PCE contamination onsite to safe levels.
According to Bishop, the regional water board may also become aware of PCE pollution when a public drinking water source, such as groundwater, is found to be contaminated with the chemical.
“DTSC has information that there could be other existing or historical dry cleaning operations in San Luis Obispo and will be conducting further investigations on potential sites in the future,” Pakkidis wrote in an email to The Tribune. “This will involve searching historical business records and performing groundwater and soil sampling.”
Although The Tribune requested an interview with DTSC staff to further clarify the state’s work with PCE contamination, Pakkidis denied those requests.
Dry cleaners linked to PCE contamination statewide
State investigations have revealed extensive PCE contamination in several major cities across California, including Fresno, Los Angeles and Sacramento.
In Modesto, for example, a complaint to the California Department of Public Health led to investigations by the state agency and the U.S. Department of Health and Human Services that revealed the PCE pollution was extensive and had seeped from dry cleaning businesses through the soil and under surrounding homes and businesses.
Near one dry cleaner in Modesto, PCE was detected in 2010 in the air of a nearby home at 200 micrograms per cubic meter, which is more than 104 times above healthy levels, according to the state’s report.
Other investigations in Modesto found PCE in the soil under dry cleaners ranging from 700,000 micrograms per cubic meter to 52 million micrograms per cubic meter.
DTSC has recently begun a comprehensive statewide investigation into PCE-contaminated sites, first looking at sites in historically underrepresented or marginalized areas, and in areas that are close to homes or other places where people could be more vulnerable to the pollution.
In total, 112 sites across the state are being investigated in 2023, according to the DTSC’s website.
None of those sites are in San Luis Obispo County.
This $152 million program “is part of the Cleanup in Vulnerable Communities Initiative to protect the health of vulnerable communities,” DTSC’s website says. “This new site discovery program will focus on sites containing dry-cleaning chemicals that have been released into the environment and could affect our communities.”
The state has also identified 21 so-called “orphan sites” across the state where it will help accelerate cleanup efforts with $40 million from the state’s Cleanup in Vulnerable Communities Initiative funding.
“Orphan sites include an array of projects that come from California’s industrial past, and as such, these represent a diverse scale and scope of hazardous substances releases that DTSC is tasked to work on each day,” the agency’s website says.
Included in these sites is San Luis Obispo’s PCE-contaminated groundwater aquifer, which the city has recently begun efforts to clean up.
The city hopes to tap into the groundwater in the next decade to diversify its water sources but cannot do so until the PCE pollution is reduced to safe drinking levels.
“Dry cleaners generally can be cleaned up to a substantial extent,” Bishop said. “The goal is to allow the city to do what it wants to do in terms of expanding groundwater production. By cleaning it up, it makes it so they don’t have to treat their groundwater (for PCE contamination) nearly as long.”
Modesto Bee reporter Adam Echelman contributed to this article.
This story was originally published February 9, 2023 at 9:00 AM.
