Effects of wastewater and combined sewer overflows on water quality in the Blue River basin, Kansas City, Missouri and Kansas, July 1998-October 2000

Samples were collected from 16 base-flow
events and a minimum of 10 stormflow events
between July 1998 and October 2000 to characterize
the effects of wastewater and combined sewer
overflows on water quality in the Blue River
Basin, Kansas City, Missouri and Kansas. Waterquality
effects were determined by analysis of
nutrients, chloride, chemical and biochemical oxygen
demand, and suspended sediment samples
from three streams (Blue River, Brush Creek, and
Indian Creek) in the basin as well as the determination
of a suite of compounds known to be indicative
of wastewater including antioxidants,
caffeine, detergent metabolites, antimicrobials,
and selected over-the-counter and prescription
pharmaceuticals. Constituent loads were determined
for both hydrologic regimes and a measure
of the relative water-quality impact of selected
stream reaches on the Blue River and Brush Creek
was developed. Genetic fingerprint patterns of
Escherichia coli bacteria from selected stream
samples were compared to a data base of knownsource
patterns to determine possible sources of
bacteria.
Water quality in the basin was affected by
wastewater during both base flows and stormflows;
however, there were two distinct sources
that contributed to these effects. In the Blue River
and Indian Creek, the nearly continuous discharge
of treated wastewater effluent was the primary
source of nutrients, wastewater indicator compounds,
and pharmaceutical compounds detected
in stream samples. Wastewater inputs into Brush
Creek were largely the result of intermittent stormflow
events that triggered the overflow of combined
storm and sanitary sewers, and the
subsequent discharge of untreated wastewater into
the creek. A portion of the sediment, organic matter,
and associated constituents from these events
were trapped by a series of impoundments constructed
along Brush Creek where they likely continued
to affect water quality during base flow.
Concentrations and loads of most wastewater
constituents in the Blue River and Indian Creek were
significantly greater than in Brush Creek, especially
during base flow. However, wastewater indicator
compound concentrations were sometimes greater
in some Brush Creek stormflow samples. Selected
stream reaches along the mid-portion of Brush
Creek showed higher effects relative to other sites,
primarily because these sites were in impounded
reaches with the greatest density of wastewater
inputs, or had relatively small drainage areas.