Some members of the water company and board have put forth the proposition that the improper shutdown of homes for the winter is the cause of coliform bacteria entering the water system. RIDoH has allowed PIWD to pursue their Cross Connection Control Program(CCCP) instead of following the state’s original chlorination orders. So, currently, PIWD is between a rock and a hard place, with RIDoH breathing down their necks on one side, and an overly ambitious plan on the other.
Roughly, here is what is being assumed and proposed:
- When cottages are shut down for the winter, the water is shut off at a “drainback valve”. This valve allows water to drain out of the cottage, but also just as easily allows external material into the water line.
- Compressed air would blow this material into the water system, contaminating the system.
- What we ought to do, therefore, is put in “backflow preventers” that would keep people from contaminating the water in this manner.
This doesn’t sound crazy, until you think a little bit harder. Here are the flaws in this logic:
- The issues don’t always occur when people are shutting down cottages. The system tested positive for coliform in July of 2018. Who was shutting down cottages then?
- The drainback valves don’t allow contaminated material into the public side of the system, even under high-pressure compressed air.
- It defies belief that material from a home could go all the way back up the hill to the “big blue tank” at detectable levels, but the bacteria is found there, every time. (And, now, as of August 2019, we can add the wells to the list of locations where coliform has been detected.)
- When the homeowner opens the cottage in the spring, contaminated material could easily flow into the home. A backflow preventer will not stop this. The PIWD has taken the position that it is OK to allow homeowners to contaminate themselves, claiming that because their responsibility ends at their curbstop, the law is on their side. However, the PIWD should answer not just to the law, but to the needs of its customers. We have to decide what we want on this issue… In a typical chlorinated system, running the water for a little while after opening your cottage would neutralize any germs.
Another interesting point is that there is a simpler explanation for how the coliform gets into the water: It could have been in there from the source wells, or entered the system along the way. Consider the following:
- The wells are routinely checked for coliform, but only once a year, in the spring, and the problems happen in the fall.
- It is well known that presence of coliform in a well is not consistent, it depends on rainfall, temperature, presence of animals in the area, amount of water drawn from the wells, etc., so light checking is not sufficient to prove that there’s no coliform in there.
- There has been coliform detected in the wells before, a few years ago, during periods of inactivity.
- Other breaks in the system, other kinds of problems could be to blame. There is a long history of finding and correcting them, but it’s like whack-a-mole.
Preventing some kinds of cross connections is good practice. There are documented cases of catastrophic depressurizations allowing chemicals to be sucked into water systems from garden hoses, sprinklers, and the like. Homeowners with both connections and wells and are high risk. But here is what some homeowners might have to do to implement the much broader Cross Connection Control Plan:
- Get a plumbing permit from the town of Portsmouth.
- Procure materials for the job. You will need a backflow preventer, and maybe a meter pit. (There are no guidelines, as of yet, on what to buy.)
- Get your water turned off. Ideally, the water company will shut off just your water, but only 80% of customers have curb stops.
- If you have a drainback valve, dig a hole in your yard, 4 feet deep, to put in a meter pit between your valve and the curbstop. 4 feet is so things won’t freeze. If the water line isn’t 4 feet down, figure out what to do about that. Alternatively, put the thing above ground. Hire an electrician to wire up a heater so it won’t freeze in the winter.
- Get a plumber to put in the backflow preventer.
- Also make sure you have a thermal expansion tank installed, so you don’t damage your water heater or pop your water filter apart leading to a flood.
- Get the backflow preventer inspected, and set up a schedule for further routine inspections.
- Get the water turned back on.
- This should be easy to do on Prudence Island, right?
So, overall, this is an insanely complex plan that won’t fix the problem. There are reasons why the Cross Connection Control Plan has been in the works for over 10 years, but hasn’t come to pass yet. Are there better solutions? Maybe, but a thorough analysis needs to be done.
- Treat the water like every other water system, with chemicals that kill germs. This might be expensive, and produce waste products, but there are no ballpark estimates available.
- Use UV light to kill the bacteria. (This will not prevent homeowners contaminating themselves.)
- Identify the real source of the coliform, and fix it. This may be a game of whack-a-mole, however, and won’t prevent homeowners from contaminating themselves.
Let’s think about what we want. Let’s discuss it!