City project would reduce hazardous runoff from old La Jolla dump site at Pottery Canyon
By Pat ShermanThe City of San Diego’s Park and Recreation department wants to stop lead and other toxins detected in the soil at a former La Jolla trash dump from leaching out when it rains.
Last week the city issued a final mitigated negative declaration (MND) on the project (No. 296100), the third such environmental report on the proposed job since an initial MND was circulated for public review May 7-28, 2013.
The project site, located directly north of land used by the La Jolla Canyon Clay Products Company from the 1930s to 1950s, and southwest of the Pottery Canyon Natural Park trail, was used as a dump by La Jollans between the 1890s and 1930s.
According to Jeffrey Szymanski, a senior planner with the city’s Development Services Department, La Jollans would burn trash from their homes, then dump it at the site. “Back then they didn’t have a landfill, so people would just go and dump their trash where they could,” he said, noting that metal and glass in the burned garbage eventually breaks down, releasing hazardous materials.
Szymanski, who is also trained as an archaeologist, said most artifacts found during trench testing conducted at the site — including old medicine bottles, metal scraps, china-ware and household goods —appeared to be La Jollans’ old household refuse, and not ceramic artifacts that could be tied to the once adjacent business started in 1928 by accomplished potter Cornelio Rodriguez (of Jalisco, Mexico) and his two brothers.
According to last week’s MND, “The research concluded that the dump site could be historically significant because it is one of the last dump sites in La Jolla and could yield important information regarding the historic period in La Jolla.”
In accordance with the city’s historical resources guidelines, as mitigation for the job, the city could have either chosen to use an archaeological data recovery program or cap the site with fill (as it did).
Soil testing conducted in 2009 determined that lead concentrations in several surface and subsurface soil samples were at hazardous levels.
In addition, other metals present in lesser quantities in the samples, including antimony, arsenic and cadmium, were at levels exceeding California Human Health-based Screening Levels for residential property use.
As part of the approximately eight-week job — intended to bring the site into compliance with minimum solid waste standards contained in the California Code of Regulations — the city would place a cap of approximately 1,000 cubic yards of clean soil over approximately 13,500 square feet of surface.
The soil would be placed on a non-woven, geo-textile fabric that would serve as a buffer.
Air quality monitors would be present during all work disturbing the soil, including minor grading and excavation, as well as an archaeologist and Native American representative to assure any potential resources or remains are handled properly, the city says.
James Royle, chair of the San Diego County Archaeological Society’s Environmental Review Committee, said that in a version of the MND released earlier this year the society found minor technical ambiguities, such as the depth of trenching tests in relation to old trash deposits, which were all addressed in last week’s final MND.
However, in a March 10 letter to Szymanski, Don Schmidt of the La Jolla Historical Society’s Preservation Committee posed several questions regarding the project. Schmidt expressed concern that the estimated 65 truck trips the project would require to deliver soil would impact traffic in the area and potentially stress or harm trees in the park.
Szymanski said the project would not require removal of trees and a biological evaluation did not identify impacts to trees.
In response to a question Schmidt raised about who will retain any artifacts uncovered during the work, Szymanski said disturbance of the dump site would be minimal and “collection of artifacts is unlikely.”
“If artifacts are discovered they would become property of the City of San Diego (Park and Recreation Department). The city will contact the La Jolla Historical Society to begin a discussion regarding the curation of any significant artifacts, if found,” he responded.
The city designated a portion of Pottery Canyon as a local historic landmark in 1976. According to Kelley Stanco, a Historical Resources Board senior planner, the designation includes a portion of private property immediately to the south of the project site, where one of the Rodriguez brothers’ kilns still sits, though not the project site or hiking trail. Several buildings related to the Rodriquez brothers’ business that were part of the designation are no longer standing.
At Schmidt’s request, a Park and Recreation Department employee will offer a presentation on the project during the La Jolla Community Planning Association’s monthly meeting, 6 p.m. Thursday, May 1, at La Jolla Rec Center, 615 Prospect St.
— La Jolla Lightwill report on the presentation in the May 8 edition.