Superfund Information Systems: Site Profile

Superfund Site:


Health & Environment

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What Are the Risks at the Site?

The chemicals that remain in soil and groundwater due to the former operations at the HP Site and nearby sites are chlorinated volatile organic compounds (VOCs), primarily trichloroethene (TCE).

Prior to the start of the environmental cleanup activities in the 1980s, potential health risks included risks from direct contact with affected soil or groundwater, accidental ingestion of affected soil or groundwater, and inhalation of chemical vapors. However, the ongoing cleanup activities have addressed these health risks and testing has shown that there are no complete exposure pathways associated with the Site.

Groundwater in the Palo Alto area currently is not used for drinking water. Drinking water in Palo Alto is supplied to homes and businesses from municipal sources including the Hetch Hetchy reservoir in the Sierra Nevada Mountains. For the sake of setting cleanup standards, it was assumed that the groundwater in the area may be a potential future drinking water source. Therefore cleanup standards protective of drinking water have been established.

Recent vapor intrusion testing results have shown elevated levels of TCE vapors in some subgrade structures (elevator shafts, underground parking garages). However, the testing has showed that there are no unacceptable accumulations of vapors in homes or workspaces.


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Contaminant Information

View a full list of contaminants of concern for this site.

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Performance Measures

EPA uses performance measures to track environmental results at Superfund sites. If you have any questions or concerns about the measures at this site, please contact the site team members listed under Site Contacts.

Read more about Superfund Remedial Performance Measures.

Status at this
Superfund Site
What does this mean?
Human Exposure Under Control Yes Yes means assessments indicate that across the entire site:
  1. There are currently no unacceptable human exposure pathways; and
  2. EPA has determined the site is under control for human exposure.

No means an unsafe level of contamination has been detected at the site and a reasonable expectation exists that people could be exposed.

Insufficient data means that, due to uncertainty regarding exposures, one cannot draw conclusions as to whether human exposures are controlled, typically because:
  1. Response to the contamination has not begun; or
  2. The response has begun, but it has not yet generated information sufficiently reliable to evaluate whether there are currently any unacceptable human exposure pathways at the site.
Groundwater Migration Under Control Insufficient Data

Yes means EPA reviewed all information on known and reasonably expected groundwater contamination. EPA concluded the migration of contaminated groundwater is stabilized and there is no unacceptable discharge to surface water. EPA will conduct monitoring to confirm that affected groundwater remains in the original area of contamination.

No means EPA has reviewed all information on known and reasonably expected groundwater contamination, and the migration of contaminated groundwater is not stabilized.

Insufficient data means that due to uncertainty regarding contaminated groundwater migration, EPA cannot draw conclusions as to whether the migration of contaminated groundwater is stabilized.

Construction Complete Yes

Yes means the physical construction of the cleanup is complete for the entire site.

No means either physical construction is not complete or actions are still needed to address contamination.

Sitewide Ready for Anticipated Use Yes Yes means:
  1. All cleanup goals affecting current and reasonably anticipated future land uses of the entire site have been achieved, so there are no unacceptable risks;
  2. All required land-use restrictions or other controls have been put in place; and
  3. The site has achieved Construction Complete status.

No means that one or more of these three criteria have not been met. However, a site listed as no may still have redevelopment occurring on portions of the site and may be eligible for additional redevelopment.

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