Environmental Engineering Reference
In-Depth Information
8
Case Studies of 1,4-Dioxane
Releases, Treatment, and
Drinking Water Contamination
Thomas K.G. Mohr
Groundwater contamination case studies provide an appreciation for the range of release modes and
contaminant behavior one might expect to encounter at different contamination sites. The rate of
migration of 1,4-dioxane relative to that of chlorinated solvents is among the more interesting attributes
of this contaminant. Migration rates rel ect both the higher mobility of 1,4-dioxane and its refractory
nature relative to methyl chloroform because 1,4-dioxane is miscible and resistant to biodegradation
and abiotic degradation. Will 1,4-dioxane be l ushed out of the aquifer by l owing groundwater and
diluted to inconsequential concentrations? Should one expect to i nd a substantial mass of residual 1,4-
dioxane near the point of release, withheld in the i ne-grained pores of silts and clays? What conditions
support persistence of 1,4-dioxane such that the quality of drinking water is degraded? The answers to
these questions are helpful for planning site characterization at 1,4-dioxane release sites.
Case studies provide useful benchmarks for the success or failure and cost of remedies selected
to treat water contaminated with 1,4-dioxane. The experience of the water utilities and the drinking
water regulators in places where 1,4-dioxane has contaminated the drinking water is helpful to
other utilities that unfortunately discover 1,4-dioxane in their drinking water supplies.
This chapter provides several case studies proi ling migration patterns, treatment solutions, and
responses to drinking water contamination.
*
Benchmarking previously studied sites to determine
solutions for another site is useful to bracket the range of possible conditions one might encounter,
but there is no substitute for i eld data from the site in question to make informed site-characterization
decisions.
8.1 SUPERFUND SITE AT SEYMOUR, INDIANA
In Jackson County, Indiana, Seymour Recycling Corporation (SRC) operated a waste chemical stor-
age and processing facility on a 14-acre property next to the former Freeman Army Air Field about
2 miles southwest of the town of Seymour, at the junction of U.S. Highway 50 and State Route 11.
The town of Seymour's population in the mid-1980s was approximately 15,300; about 100 homes
were located within a 1-mile radius of the SRC site (USEPA, 1986). SRC processed, stored, and
incinerated chemical wastes at the site from about 1970 to early 1980. Most of the area immediately
surrounding the site is used for agriculture. Approximately 100 residences and businesses relied on
private wells that used groundwater from the shallow aquifer near the site before these users were
connected to a municipal water system. The neighboring Freeman Municipal Airport obtains its
water supply from a well completed in the deep aquifer (USEPA, 1987).
*
The sites in these case studies were all characterized by professional geologists and engineers who have a great deal more
familiarity with site conditions than the author; any unintended misrepresentation of site conditions is the responsibility
of the author alone.
369
Search WWH ::
Custom Search