Swift
Creek Reservoir Threatened by Highway Construction Run-off
Mud plumes from construction of the 288 corridor and the recent
rains have now entered the main body of Swift Creek Reservoir. Chesterfield County Officials have been alerted that the main
plume could reach the water treatment plant as early as three four days.
Hands Across the Lake (HAL), an environmental group working
for the protection of the reservoir, believes that water is more important than roads. HAL requests VDOT and other major construction
projects halt further earth disturbing activities in the Swift Creek Watershed until an acceptable sediment containment solution
is implemented.
Last October, the Virginia Department of Health (VDH) issued
a Source Water Assessment for Swift Creek Reservoir and the Addison-Evans Water treatment Plant as mandated by the 1996 amendments
to the Safe Drinking Water Act. In this report, VDH listed five highway construction projects by VDOT as a potential source
of contamination for the reservoir. Route 288 construction was one of these listed projects.
Mud plumes pollute the reservoir because they carry silt,
high nutrient loads, decayed organic matter and possibly other substances that VDH considers harmful to public drinking water.
Nutrient loads are normally controlled by settling ponds (BMPs) and vegetated buffers along stream banks that keep mud and
nutrients (phosphorus) contained. (Keeping phosphorus levels below dangerous
thresholds is a key management strategy for the reservoir). The silt is of concern
since it fills in the reservoir and destroys the bio-diversity of the creeks. Decayed
organic matter reacts with the disinfection process to form disinfection by-products (DBPs). Many of the DBPs are carcinogenic
but are not measured on a daily basis. The concentration at which adverse health effects may occur is a subject of extensive
study. VDH or Chesterfield County Health Department may wish to require additional
testing or procedures during this crisis.
In May 2002, similar plumes discolored the reservoir north
of Genito Road and were traced to the intersection of Route 288 (under construction) and the two creeks. The county reported
that Little Tomahawk Creek had high base loads of sediment in addition to the mud plumes after a rain. County staff provided
aerial and creek-bed photo-documentary evidence of the pollution problem to VDOT and state officials. VDOT in conjunction
with DCR reportedly installed a remedy.
These remedies are not working well enough to protect this
valuable county water source. The county is trying to set up an emergency meeting with VDOT officials either Monday or Tuesday
to discuss the problem and hopefully come up with a remedy that protects the water.