Ground Water Under Direct Influence of Surface Water (GWUDI)
July 8,2018
the staff of the Ridgewood blog
Ridgewood NJ, Ridgewood Water completed a year-long study of its supply well system to evaluate the vulnerability of the wells to microbiological contamination from nearby surface water bodies.
Ridgewood Water performed the GWUDI study under a rigorous Source Water Monitoring Plan which was approved by the EPA. The study involved the collection of water samples from up to 38 wells and three surface water locations on a weekly and biweekly basis. The samples were analyzed in the laboratory for evidence of microbiologic activity and for other “indicator parameters” that may indicate surface water influence.
All samples were collected and analyzed by an NJDEP-certified laboratory and were reported on a quarterly basis to the NJDEP and EPA.
Group 1 Wells (2 locations)For the two Group 1 wells, EPA determined that the occasional presence of of e.coli in raw water required further assessment to determine whether there is evidence of a direct connection of these sources to surface water. Ridgewood performed weekly raw water monitoring at the two Group 1 wells for the presence of fecal coliform, e. coli and turbidity.
GROUP 1
Franklin- 2016 Q3, Q4
Mountain- 2016 Q3, Q4rformed weekly raw water monitoring at the two Group 1 wells for the presence of fecal coliform, e. coli and turbidity.
Group 2 Wells– (3 locations)
For the three Group 2 wells, EPA determined that the occasional presence of of e.coli in raw water required further assessment to determine the degree of influence of nearby surface water on each well and whether there is a need for additional treatment. Ridgewood Water performed weekly raw water monitoring at the two Group 2 wells for the presence of fecal coliform, e. coli, aerobic spores, pH, temperature and turbidity. Ridgewood also performed weekly surface water monitoring at associated surface water bodies for the same parameters. The third well has been shut down and is being reevaluated for reconstruction or permanent closure.
GROUP 2
Carr #7- 2016 Q3, Q4
Goffle Brook- 2016 Q3, Q4
Ho-Ho-Kus Brook- 2016 Q3, Q4
Newtown- 2016 Q3, Q4
Group 3 Wells – (33 locations)
The 33 Group 3 wells have not exhibited any evidence of being under the influence of surface water. These wells were previously screened by NJDEP and were not found to warrant additional assessment. As such, the NJDEP issued monitoring waivers to Ridgewood for these wells. EPA has determined that a further assessment of these wells was warranted. The monitoring consisted of biweekly raw water sampling and analysis for e.coli bacteria.
Ridgewood also performed Hydrogeologic Sensitivity Assessments (HSAs) of all Group 3 wells. These are reviews of the conditions and potential sources of surface contamination at each location to assess their vulnerability to future microbiologic contamination.
GROUP 3
Ackerman- 2016 Q3, Q4
Ames #5- 2016 Q3, Q4
Ames #6- 2016 Q3, Q4
Carr #1- 2016 Q3, Q4
Carr #3- 2016 Q3, Q4
Carr #4- 2016 Q3, Q4
Carr #6- 2016 Q3, Q4
Cedar Hill #1- 2016 Q3, Q4
Cedar Hill #6- 2016 Q3, Q4
East Ridgewood- 2016 Q3, Q4
East Saddle River- 2016 Q3, Q4
Eder- 2016 Q3, Q4
Fairview- 2016 Q3, Q4
Glen Rock- 2016 Q3, Q4
Grove- 2016 Q3, Q4
Irving- 2016 Q3, Q4
Lakeview- 2016 Q3, Q4
Main- 2016 Q3, Q4
Meer- 2016 Q3, Q4
Midland- 2016 Q3, Q4
Paramus- 2016 Q3, Q4
Russell- 2016 Q3, Q4
Salem- 2016 Q3, Q4
Spring- 2016 Q3, Q4
Twinney- 2016 Q3, Q4
Van Houten- 2016 Q3, Q4
West End- 2016 Q3, Q4
Wortendyke #2- 2016 Q3, Q4
Wortendyke #6- 2016 Q3, Q4
Wortendyke #7- 2016 Q3, Q4
