Runoff From Roads and Highways

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 Plymouth wellhead.
 
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 leightonaprice@yahoo.com or call Leighton A. Price at 508-930-4551.