1601 Mariposa Street to Undergo Environmental Impact Review
In a surprise move, last month Related California offered to undertake an environmental impact review of its proposed project at 1601 Mariposa Street. The move was in response to Potrero Hill residents’ concerns about hazardous materials on the site, as well as other health and safety issues. Residents are also worried about the project’s size and density.
“We are advocating for a focused EIR,” said Rick Westberg, Related California’s vice president of development. The company had initially requested an EIR exemption, pointing to reviews that were done under the EIR established by the Eastern Neighborhoods Plan as being sufficient.
“I want things to stay nice for the kids,” said Alison Heath, a member of the neighborhood advocacy group, Grow Potrero Responsibly. Heath made her comment at a community meeting held last month at Live Oak School, which is located adjacent to the proposed project. International Studies Academy is also nearby.
According to Westberg, a geotechnical review done for Related found that the serpentine rock on the site doesn’t pose health hazards. Westberg said that soil on the area’s western side contains granular amounts of serpentine rock that can be disposed of by scooping it up while controlling the dust. And Related won’t be digging into the ground. “We’re not breaking into bedrock,” Westberg said.
He also said Related will cleanup any hazards associated with the underground storage tanks (USTs) on the site. Residents have expressed concern about benzene, which can cause cancer after long-term exposure, according to the Centers for Disease Control and Prevention, and can be emitted from leaks from USTs. According to Westberg, the USTs on the site were sealed twenty to thirty years ago. But, he said Related wants to “make sure it’s safe.”
Related wants to build 320 apartments on the 3.4 acre site, which Grow Potrero Responsibly member Holly Friedman said is “too big, too soon.” Grow Potrero Responsibly has started a petition opposing the project, which has gathered 362 supporters. “We want the neighborhood to be improved,” said Claude Everhart, who once worked for former San Francisco mayor and Hill resident Art Agnos. “We just don’t want so much of it.” Among other concerns, Grow Potrero says the project’s density is out of character with the Hill.
Lydia Tan, Related’s executive vice president and director, northern California operations, presented two measures of density and compared its proposal’s density with two other Hill projects. According to Tan, 1601 Mariposa is proposed for 96 units per acre, compared with 91 units per acre at 1130 Mariposa and 91 units per acre at 450 Rhode Island Street. Tan also compared the number of bedrooms per acre. Related is proposing a density of 137 bedrooms per acre, compared with 113 for the development at 18th and Arkansas and 121 for Victoria Mews. Grow Potrero Responsibly claims that Related’s proposal is four times as dense as Victoria Mews.
Related also compared the floor area ratio of its proposal with three other sites and the City-allowable ratio. The City allows for a ratio of 3; 450 Rhode Island Street has a ratio of 2.61, Live Oak School has a ratio of 3.77, and 1130 Mariposa has a ratio of 3.02. Related is proposing a ratio of 2.30 for 1601 Mariposa Street. According to the San Francisco Planning Code, floor area ratio is defined as the gross floor area of all the buildings on a lot compared to the lot’s area. For example, a two-story building that covered the entire lot would have a floor area ratio of 2:1.
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