Signs have sprouted around the edges of Echo Park Lake informing visitors of an upcoming project to drain and clean up the lake’s waters, which are contaminated with everything from trash to traces of toxic compounds. One of the many challenges to keep those waters clean after the $64.7 project is completed are toxic solvents that have over the decades seeped into the ground underneath the Holloway Cleaners building at the corner of Echo Park Avenue and Sunset Boulevard. It’s been more than 20 years since state environmental officials found evidence that toxic chemicals commonly used in the dry cleaning business – Perchloroethylene (PCE) and Trichloroethylene (TCE) – had contaminated the soil and groundwater underneath the three-story building. A plan to monitor and deal with that contamination was put in place, and the dry cleaners, which has changed hands over the years, now abides by hazardous waste disposal practices, according to a city official. But the environmental damage had already been done.
In early 2009, more testing discovered that a block-long plume of PCE in the groundwater had slowly spread south from the dry cleaners to the northern edge of the lake, according to the 478-page environmental impact report on the lake rehabilitation project. The report warned:
“Concentrations of PCE, TCE, and 1,2-DCE levels above applicable [state water quality agency] thresholds were detected at the [lake] project site. As such, contaminated groundwater plumes migrating from Hollyway Cleaners toward Echo Park could potentially pose an ecological and hydrological threat.”
It’s still not clear if that PCE from the dry cleaners have actually seeped into the lake, said Michelle Vargas, a spokeswoman with the city’s Department of Public Works, which is overseeing the lake rehabilitation. But officials overseeing the lake rehabilitation are taking no chances.
The environmental report said that the building of temporary wall along the northern edge of the lake and the drilling of temporary wells would help prevent groundwater contaminated with PCE and TCE from spreading to the lake when its waters are drained during the construction. A new clay liner along the bottom and walls of the lake will help to keep those chemicals out. In addition, the environmental report said the city must work with state water quality officials “in order to ensure that the PCE plume migrating offsite does not pose an ecological and hydrological threat to Echo Park Lake.”