The industrial swath that hugs the Bay between Hunters Point and East Palo Alto years ago contained so much contaminated land that some environmental groups dubbed it the "toxic crescent."
Today, there are more than 550 known contaminated sites in San Mateo County.
While that figure is formidable, it is about 39 percent smaller than it was 10 years ago, and is continuing to shrink, according to the two state agencies that oversee toxic cleanups.
And the drive behind the cleanup is simple.
"Development," Department of Toxic Substance Control spokeswoman Carol Northrup said. "Development is cleaning up sites that otherwise wouldn’t be cleaned up."
August will mark the 30th anniversary of President Jimmy Carter’s declaration of a federal emergency at the Love Canal neighborhood of Niagara Falls, N.Y., a community built on a toxic dumpsite that proved replete with health problems and birth defects.
The incident caught the nation’s attention and focused it on the poisons in its soils, spurring Congress to expand the powers of the Environmental Protection Agency, create the Superfund program to identify contaminated sites and force polluters to pay.
In the years to follow, San Mateo County, like the rest of the nation, was scrutinized for sites where underground storage tanks may have leaked, where dirty industries may have been careless with chemicals and where the military may have left unwanted waste.
Though Northrup remembers a time when state environmental agents literally went through the phonebook in search of toxic sites to possibly forcibly clean up, "the whole thing has flipped around," she said.
"Now the real estate market is driving it. They say, ‘I really need that piece of property,’ and come to us to help them clean it up," she said.
In areas such as the Peninsula, where land is in short supply, there’s an even stronger interest in "brownfields," or land that otherwise would have little or no value due to contamination, she said.
One such instance is the 18-acre lot on San Carlos’ Industrial Road where the Palo Alto Medical Foundation plans to build its new hospital. The land once housed a power-grid tube company that contaminated it with various oils and solvents.
Medical Foundation spokesman Ben Drew said the contamination didn’t deter the foundation from purchasing the site.
"There aren’t many big sites available on the Peninsula, and we really like the location and the access," he said. "We felt very confident it could be cleaned up — we wouldn’t have gone any place where we didn’t think we could provide a safe and healthy place for our patients and staff."
It’s not uncommon to see cities eye brownfields too. Redwood City’s redevelopment agency is in the process of cleaning up a 1-acre site downtown, at a cost of about $100,000, to build a much-needed senior-housing complex.
Jeannie Young, a city project manager, said cleaning up a contaminated site and building housing on it fits perfectly within the city’s vision.
"We’re revitalizing our community," she said.
The Peninsula is peppered with former military sites that have never been thoroughly checked for unexploded ordnance or toxic contamination, and officials say that examination might not happen for 100 years or more.
According to the state’s Department of Toxic Substance Control, San Mateo County contains 21 former military sites — comprising at least 3,200 acres — that have been identified by the Army Corps of Engineers as former military land that could be contaminated.
Since those sites were identified in the mid-1980s, only one has been thoroughly evaluated: a 340-acre site at the Half Moon Bay Airport, where two underground storage tanks were found and which may be contaminated by gas or diesel.
The remaining sites range from a 14-acre former explosives battery in Pacifica, where unexploded ordnance could potentially still lay, to the site the San Francisco International Airport now sits on in San Bruno. Some of the land is now being used actively, but the military still has the responsibility to study the land and see if there remains any undetected ordnance or contamination, said DTSC supervisor Donn Diebert.
However, the program has been "woefully underfunded," Diebert said, and the process has been very slow going. There are more than 1,000 former military sites in California alone, and mitigating those sites would cost $2.2 billion, according to Diebert. As it stands, the federal government allocates $20 million to the program.
At this rate, it will take between 80 and 120 years to attend to every site on the list — including San Mateo County’s, he said.
Various sites that are known to be contaminated.
Midway Village, Daly City
» History: A low-income housing complex built on contaminated dirt from a nearby Pacific Gas and Electric Co. gas plant. A cleanup was completed, but residents still blame the contamination for ongoing health problems.
» Contaminants: Polynuclear aromatic hydrocarbons (PAHs) in the soil and groundwater.
» Status: State officials say the site is clean, but residents continue to ask to be relocated.
Burlingame High School, Burlingame
» History: Environmental testing in 2003 found a variety of contaminants on school grounds.
» Contaminants: Arsenic, lead and PCBs in the soil.
» Status: The school immediately fenced off appropriate areas and will complete its cleanup by September.
Proposed Charter School, Redwood City
» History: The site of a Baptist church and Montessori School was inspected in 2006 for potential use as a charter school. Slight levels of contamination were found.
» Contaminants: Lead, pesticides and PCBs in the soil.
» Status: The district has postponed any projects for the land, but the private school and church are still in use.
Gibson Environmental Facility, Redwood City
» History: The 8.9-acre site was used by Texaco and other companies to store and transfer fuels and as a hazardous-waste treatment facility before being abandoned in 1995.
» Contaminants: 10 million gallons of fuels and other hazardous waste in tanks and soil.
» Status: The Port of Redwood City continues to clean the site and attempts to contain the site’s strong odor.
Romic Environmental Technologies Corp., East Palo Alto
» History: The facility processed hazardous industrial wastes since the 1950s, but was repeatedly cited by the state for violations and chemical spills, before shutting down last year.
» Contaminants: Volatile organic compounds (VOCs) in the soil and groundwater.
» Status: The site has been sold to a new company, and a cleanup is ongoing.
Peninsula Corridor Project, San Mateo County
» History: The 50-mile-long railroad right of way between San Francisco and San Jose has been an active corridor since 1863.
» Contaminants: Arsenic, lead, diesel, motor oil and PAHs.
» Status: Caltrain has so far excavated two 100-square-foot areas of lead-impacted soil.
Bradford Street Parcels, Redwood City
» History: The land, once probably backfilled with contaminated soil, may be the future site of a senior housing complex.
» Contaminants: PAHs may contaminate surface water.
» Status: Redwood City is in the process of cleaning the site to state standards.
Southern Pacific, Brisbane
» History: The 180-acre site, 2,000 feet west of the Bay, was used by Southern Pacific Transportation Company for railcar maintenance.
» Contaminants: Waste oil, chromium, copper, zinc, lead and arsenic.
» Status: More than two million gallons of toxins have been removed from the site. Long-term monitoring and more cleanup is planned for coming years.
G-C Lubricants Co., San Carlos
» History: The property has long been used as a lubricating-oil packaging facility and was once leased to an oil recycler.
» Contaminants: High concentrations of PCBs, VOCs and other toxins in the soil and groundwater.
» Status: One part of the site has been capped. The plant continues to operate, and remediate the toxins.
Sharp Park Rifle Range, Pacifica
» History: The 6-acre site, now owned by the city and county of San Francisco, operated as a firing range for shotguns, rifles and handguns from 1952 to 1988.
» Contaminants: Lead shot.
» Status: A voluntary cleanup of the site may be complete by 2009.
There are 557 sites in San Mateo County known to be contaminated, with 507 of the sites contaminated by underground storage tanks or other spills or leaks. A breakdown of the 507 sites in major cities in the Peninsula:
South San Francisco: 96
Redwood City: 86
San Mateo: 67
San Carlos: 49
Daly City: 29
All others: 180
Source: Sustainable San Mateo County, Department of Toxic Substance Control
39 Percent fewer contaminated sites in San Mateo County compared with 1998
5 Cities in the county with more contaminated sites in 2007 than in 2006, indicating newly contaminated or discovered sites (Burlingame, Daly City, East Palo Alto, Pacifica and San Carlos)
21 Sites in San Mateo County formerly used by the military and unevaluated for potential contamination by toxins or unexploded ordnance
1,096 Such sites in California
$2.2 billion Cost to clean up all the former military sites in California
$20 million Average amount devoted to cleaning up California’s former military sites
1 Site in the county in the federal Superfund program, a location in East Palo Alto that once was home to a pesticide manufacturing plant
30 Years in August since President Jimmy Carter declared a national emergency for the Love Canal neighborhood in Niagara Falls, N.Y., after unprecedented numbers of residents began becoming sick from toxic waste left on the site. The incident sparked the national movement to clean up contaminated sites
Source: Department of Toxic Substance Control, San Mateo County Department of Public Health, Regional Water Quality Control Board