Case Studies: Successful and Unsuccessful Redevelopment of Contaminated Sites - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 481

• The application of effective urban investigative and geologic forensic techniques
such as conducting a comprehensive site history and the knowledge of contami-
nant fate and transport can identify potential anthropogenic effects at a site.
• Anthropogenic influences may reduce the synergistic effects resulting from cer-
tain combinations of geology and high-risk chemicals. This effect is apparent
where groundwater is shallow, in short supply, and the constructed infrastructure
works to prevent the downward movement of the contamination (e.g., storm sew-
ers and building foundations).
• Anthropogenic infrastructure can influence migration pathways, complicating
environmental investigative and remedial efforts.
• The fate and migration of lead, PCBs, PAHs, and SVOCs released into a geologic
environment of shallow groundwater indicates these compounds did not migrate
a significant distance laterally. Their relative immobility arises from the nature of
the compounds—they have a high soil contaminant risk factor.
• Outdoor storage areas offer potential sites for contaminant release.
• Low points in and around buildings can act as effective conduits of contamina-
tion; sources of contamination were sumps, trenches, and floor drains.
• Successful redevelopment of a damaged site is possible. Here, a city park and con-
version to other land uses is in progress.

14.6 Case Study 5: California
Case Study 5 is located in an urban area in California (DTSC 2006). It became a brownfield
site when shut down after 36 years of operation. According to available records, it was first
developed as a chrome plating facility in 1966 and operated until 1999. Table 14.5 lists some
basic information concerning the site.

TABLE 14.5
Site Characteristics of Case Study 1 Located in California

Characteristic Site Information

Location California

Years of operation 36 years

Size of property 2 ac

Geologic setting Alluvial and fluvial sediments

Soil type and stratigraphy Sand interbedded with some fine silt and clay

layers.

Contaminants detected Chromium VI, lead, cadmium, nickel, and mercury

COC for soil Lead, mercury, cadmium, and chromium VI

COC for groundwater Chromium VI

Depth to groundwater Approximately 21 m (70 ft) beneath the surface of

the ground

Highest CRF GW ranking 2300 chromium VI

Highest CRF SOIL ranking Mercury 15,600

Geovulnerability ranking 63