The nearly 70-acre portion of San Francisco’s waterfront known as Pier 70 is saturated with footnotes of San Francisco history. For more than a century, the site was dedicated to the shipbuilding and manufacturing trades (ship-repair work is still performed there). Considered the center of heavy industry in the Western U.S. for decades, the site began industrial operations in the 1800s, with ships built there as far back as the Gold Rush. More recently, Pier 70 served the needs of Bay Area commuters as the staging grounds for an essential piece of mass transit. And although its past uses helped shape the region we know today, they are also now triggering a multimillion-dollar environmental cleanup effort needed at Pier 70 before it writes a new chapter. CHANGING WITH THE TIMESIn the near future, about a third of the plot of land located south of Mission Bay could become home to at least 1,000 San Francisco residents, waterfront parks, new space for existing artist studios, and ground-level manufacturing and retail services. The development would expand The City’s Dogpatch to the waterfront for the first time in San Francisco history. Amid the clamoring for more housing and open space in a rapidly growing San Francisco, the mixed-use development at Pier 70 won voter approval Nov. 4 for a height-limit increase with the passage of Proposition F. Numerous community groups say the developer of Pier 70, Forest City, has done well to include the community in plans for the site since winning the bid in 2011 for the project, marking possibly the first time a waterfront project has received such widespread support in San Francisco.The project had to go to the ballot for the height increase from 40 to 90 feet because in June another measure was passed that requires voter approval for such increases on Port of San Francisco-owned waterfront property. That followed failed ballot initiatives last year over a contentious luxury condo development at 8 Washington St. near the Ferry Building — one that received various city approvals required to move forward but ultimately failed to win over voters. A lawsuit from the state of California against San Francisco over the height-increase measure is pending. Regardless, Forest City went to the ballot and succeeded where others failed. Now an environmental review is among the next steps it must take before building its mixed-use development. And an investigation by the Port several years ago revealed that soil contaminants could pose a risk to future site users under certain exposure scenarios. HISTORY OF PIER 70 The site that is called Pier 70 today has never been shy about making its mark in San Francisco and U.S. history. At a time when heavy industry was booming on the East Coast, Pier 70 attracted such factories and enterprises to the West in the 1800s. “It was just a magnet for workers and manufacturing for such a long time,” said Ralph Wilson, a member of the Central Waterfront Advisory Group for the Port of San Francisco. “It was sort of the first of the West Coast defense industry locations.” In the late 1880s, Pier 70 became the first West Coast site to build a Navy ship, which had previously only been constructed on the East Coast. Union Iron Works, which owned and operated the site from 1885 to 1905, went on to build several famous ships there that were used in the Spanish American War, Wilson noted. The site continued to employ much of the heavy-industry trade when Bethlehem Steel began operating there in 1905. Just before the U.S. entered World War II in 1941, machinists staged a strike at Pier 70 that lasted several months, marking a crucial time for the country as it strove to build the capacity at its shipyards before going to war. Pier 70’s history even touches present-day San Francisco: The tubes that carry BART trains through San Francisco Bay were built at Pier 70 in the late 1960s, said Wilson. CONTAMINATION The decades of heavy industry and shipbuilding no doubt took their toll on the environmental quality of Pier 70. Using data from investigations dating back to 1989, Port of San Francisco officials confirmed various contaminants exist at Pier 70. Several investigations and remediation efforts have been conducted at Pier 70 between 1989 and 2011, culminating in the most recent investigation in 2009 and 2010, according to a May 2012 Port of San Francisco report that outlines a cleanup plan for the area. The soil at Pier 70 contains naturally occurring metals and asbestos from both the historic fill and the historic industrial operations, and heavy hydrocarbons that are typical of bayshore fill material.Soil gas samples, on the other hand, found negligible contamination, said Carol Bach, environmental and regulatory affairs manager for the Port of San Francisco. The groundwater contains the same contaminants, but not at concentrations that pose a risk to site users or San Francisco Bay water quality, she said. Additionally, nonvolatile, insoluble, highly viscous hydrocarbons are present beneath portions of the BAE Systems San Francisco Ship Repair facility, which continues to mend vessels at Pier 70 today. But finding such contaminants at the site was not particularly surprising for land along San Francisco’s waterfront, Bach noted. “Pier 70 has a long history of industrial use,” said Bach. “The soil at Pier 70 is comprised largely of fill material that was either brought to the site to build new land or created serpentine rock bluffs that formed the shoreline in that area.” However, there is also a small area in the southeastern portion of Pier 70 where dense nonaqueous-phase liquid (DNAPL) hydrocarbon contamination from former power plant operations at the adjacent site, where PG&E previously operated the Potrero Power Plant, has migrated north and is present in two localized areas beneath Pier 70. PG&E has a plan to address the DNAPL at both sites and excavate the contamination from underneath Pier 70 beginning in October 2016. NEXT STEPS The Port of San Francisco has developed a site-specific plan that has been approved by the Regional Water Quality Control Board to tackle the contaminants found at Pier 70. The plan, selected by the Port from a number of possibilities, involves placing durable covers over the contaminated soil. Durable covers, or caps, include new or existing building foundations, streets, sidewalks, hard surfaces or paved parking areas. New landscaping that consists of at least two feet of clean imported soil separated from the existing soil by a demarcation layer, or six inches of gravel over a demarcation layer, would also suffice. Bach emphasized that much if not all of the contaminated soil in areas used by people at Pier 70 is already covered. “Virtually all of the soil that people can access at Pier 70 is currently covered with paving or buildings or some kind of durable cover already,” Bach said. The Port has estimated that implementing the barriers will cost $8.5 million, though Bach emphasized that because the work will be undertaken during development that figure may vary. “The remedial action is part of the project development, and the cost is sort of embedded in that,” Bach explained. The durable covers at Pier 70 would extend to the shoreline, where the cover would be engineered and integrated with shoreline protection. At the shoreline, a barrier cover would prevent erosion. In addition to its continued outreach efforts, Forest City will conduct its analysis under the California Environmental Quality Act within the next 18 months, Alexa Arena, senior vice president for Forest City, said in a statement to The San Francisco Examiner. “Environmental remediation activities for the project will be addressed in detail as part of the environmental review and planning processes,” the statement said. If ignored, the contaminants found in the soil at Pier 70 could lead to health risks such as cancer, but Port officials emphasized that any such risks from the contaminants will be addressed by risk management measures inspected annually by the Port. These easures include dust control procedures, requiring health and safety protection for workers and not allowing groundwater to be used at Pier 70.