Contamination
from Highway, Road and Driveway Runoff?
Overview
The Six
Ponds Association’s water quality work continues to identify problems which may
require attention and remediation.
Much of our
work to date has focused on the nutrient pollutants, phosphate and nitrate, and
the concentrations of e-coli in our ponds, but recent analyses of our data have
caused us to consider the possible impacts of other contaminants. Specifically,
we have found that salts, components of salts, and other contaminants often
seen in highway, road and driveway runoff are showing up in some of our ponds.
Moreover, the three ponds with the highest concentrations are those closest to
paved roadways where storm drains and the roads themselves channel runoff
directly into our ponds or onto land close to our ponds.
These
results may have implications for road construction, storm drain construction
and best management practices (BMPs) for remediation in the vicinity of water
bodies. The BMPs recommended for remediating runoff problems are retention
systems and these are usually paid for with 604(b) government grants. Six Ponds
applied unsuccessfully for a 604(b) grant several years ago, but, given our
recent findings, we think it is important to try again.
We have
long suspected that stormwater runoff may be affecting our ponds in many ways,
but we have not had sufficient data for clear patterns to emerge. Statistical
processing of the chemical analyses of more than 150 water samples has now
revealed interesting and disturbing patterns which strongly suggests that road
runoff is having an impact.
With regard to seven chemical parameters suggesting
runoff problems, we have found Bloody Pond to have the highest quantities, Little
Long Pond to be next highest, Long Pond third, Halfway Pond fourth, Round Pond
fifth, and Gallows Pond to have the lowest quantities.
Plots
showing the results obtained for each of the seven parameters detected and
discussion of these results are available through a web link below.
In the
discussion, we have tried to understand how the observable characteristics of
each pond may contribute to the findings. To that end, we have examined housing
and terrain characteristics, the types of roads surrounding each pond, and some
of the drainage characteristics which may contribute to runoff problems for
each pond. Another web link below will take you to an interpretation of why we
think the quantities of the seven runoff parameters involved may be related to
the amounts of stormwater runoff being discharged into our ponds from paved
roads and storm drains.
Initially,
the findings for Bloody Pond surprised us until a site visit revealed that
multiple stormdrains from Route 3 and ditches in a wetlands area shunt
stormwater to the pond. This finding has special significance because the pond
lies in an officially designated acquifer protection area which also contains a
possible location for a
We trust
that you will be persuaded by our discussions of the results for all the ponds
in the Six Ponds area.
If you
have observations and pictures to contribute to this discussion, please send
e-mail to input@plymouthwaterquality.org
or call Leighton A. Price 508-224-3441.
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Sampling and Chemical Analysis
Database and Statistical Analyses
Related
Information
Also,
please see the following web site(s)
Is Highway Runoff a
Serious Problem?