Water Quality

Water Quality Data


The North Kingstown Department of Water Supply is governed by the Safe Drinking Water Act. Enacted in 1974, it required the US Environmental Protection Agency to establish drinking water regulations designed to ensure safe drinking water. The law requires us to sample our water for over 100 regulated and unregulated contaminants. We supplement the required data with voluntary monitoring of our wells, storage tanks and distribution system. We are always happy to share our water quality data with you. It is important to us that our customers feel confident that the water they use is safe. If you would like a description of our water quality monitoring program, a copy of our Consumer Confidence Report or any other water quality information please contact the Department of Water Supply at (401) 268-1522 or 268-1520.

North Kingstown Department of Water Supply Total Coliform Testing Facts

Total Coliform – Fecal Coliform – What’s the difference?

Coliforms were chosen as indicators of microbial contamination of water in the 1880s. Total Coliforms are considered an indicator of overall water quality and treatment efficiency. There is no correlation between Total Coliform and human health, it is an indicator species group only – when Total Coliform is detected in a water sample it is assumed that conditions within the water distribution system are favorable for bacterial growth and pathogenic (disease causing) microorganisms may be present. Fecal Coliforms are a subgroup of the Total Coliform organisms.

Where are the samples taken from?

The North Kingstown Department of Water Supply collects samples on a weekly basis from sampling stations located throughout the water distribution system. The testing sites include all five of the system storage tanks and 13 other dedicated sampling stations. While it is not a requirement of the Total Coliform Rule (TCR), the Water Department also collects weekly samples from the ten (10) water supply wells.

How are samples analyzed?

The samples are analyzed for Total Coliform Bacteria and Fecal Coliform Bacteria at a licensed laboratory. The testing method requires that filtered samples be incubated at certain temperatures. It takes between 48 and 72 hours to receive confirmation of the presence of Total Coliform bacteria. Presumptive results are available after 24 hours of incubation. Presumptive results are an indication that Total Coliform may be present. It takes an additional 24 hours to determine if Fecal Coliform is present and if it is not, it may take an additional 24 hours to confirm the presence of Total Coliform.

What happens if a sample is positive for Total or Fecal Coliform?

In accordance with the TCR, if any routine sample is Total Coliform positive it must be analyzed for fecal coliform. If any sample is found to be Total Coliform positive, the water system must collect a set of repeat samples for each positive sample. The repeat samples confirm the presence of Total Coliform bacteria in the distribution system. A sample must be collected from the sampling station that had the initial positive sample and samples must also be collected from locations upstream and downstream of that sampling station. In most cases these upstream and downstream locations are kitchen or bathroom faucets in homes or businesses located around the sampling stations.

Total Coliform

In accordance with the Total Coliform Rule, five (5) percent of a water system’s monthly samples can be Total Coliform positive. A water system is in violation of the rule if more than five percent of its monthly samples are positive. Such a violation requires that a public notice be advertised in the newspaper acknowledging the violation. This type of violation does not result in a boil water advisory.

Fecal Coliform

If Fecal Coliform is detected in a routine sample the water system must notify the RI Department of Health within 24 hours of learning of the positive sample. As above, repeat samples must be collected. If either Total Coliform or Fecal Coliform is detected in any repeat sample, the water system is in violation of the Total Coliform Rule. This type of violation is considered an acute violation and results in the issuance of a boil water advisory. Under our current approved sampling schedule, routine samples are collected on Tuesday. We receive the presumptive results from the laboratory at the end of the day on Wednesday. Repeat samples are collected on Thursday and the confirmation of the results of the repeat sample analysis are not available until Saturday or Sunday. Sometimes presumptive positive results do not confirm, which is why boil water advisories are not issued on presumptive results.

Backflow and Water Quality

Consider this scenario if you will: It’s a typical busy day in Anytown, USA. On Main Street, the kitchen staff at the Village Diner is busy cleaning up after the big lunchtime rush. On Maple Street, Mrs. Jones is diligently watering and fertilizing her gardens using a handy hose attachment that injects liquid fertilizer into the water streaming out of her hose. Mr. & Mrs. Smythe on Oak Ridge Terrace are standing on their deck overlooking their expansive backyard, watching the initial operation of their new in ground sprinkler system. The Johnson’s, anticipating a great turnout for their daughter’s birthday party, are filling up the big wading pool that they just purchased. And down on Old Mill Street the driver from EZ Septic Services is washing out the septic tank of the house he’s working at, utilizing the garden hose at the house, just like he always does. But unbeknownst to all these folks, out on Route 1, Whoopsie Construction Company is working putting in a new underground fiber optic cable that’s going to make everyone in Anytown’s life just a little better; or so they all think.

You see, at just the moment that all those everyday activities are going on in Anytown, the excavator operator for Whoopsie Construction accidentally punctures the major 16” water main that feeds the entire community. And, as water rushes out of the broken main at the construction site, a rapid pressure drop occurs throughout the Anytown Water System and a backflow situation occurs. Simultaneously, a portion of the dirty water in the slop sink at the diner is suctioned into the town’s water system through the sprayer hose, a portion of Mrs Jones’ fertilizer goes not on her roses, but into the main on Maple St., the puddles in the newly pesticide and herbicide treated lawn at the Smythes’ place disappears into the water system on Oak Ridge Terrace, the water in the Johnson’s pool is suctioned back into their hose and home piping rather than flowing out into the pool, and last but not least, a small portion of the wash water from the hose hanging into that septic tank contaminates the water mains all around Old Mill Street.

Sound preposterous, or impossible – well its not. This all happened because out in Anytown USA, they do not have an active backflow prevention program.

Backflow preventors, whether they be a simple residential model or a more complex and protective device for use in industrial settings, are designed to prevent just the kinds of scenarios described in our imaginary story about Anytown. Any inconvenience or expense involved with the installation of these devices is far outweighed by the protection they afford. Don’t let your town end up like Anytown; insist upon appropriate backflow prevention.