Drainage issues at Ocean Street and Plymouth Ave

Good morning everyone!

I am sure that all of you are aware of the drainage issues we have been dealing with for the past month at Ocean Street and Plymouth Avenue. I am emailing all of you just to give you all a brief synopsis of what has been done thus far, what we have encountered, what may be the issues and what we are proposing to do short term:

  • What we have encountered: To date, we have a tremendous amount of water pouring into our drainage system, hundreds to thousands of gallons per minute every day. For a period of time we could not figure out where it was coming from. Last week we pulled up a plan showing all the infrastructure on Ocean Street as well as the intersection of Plymouth Avenue. On the drawing we noticed an abandoned twelve inch water main that intersects our drainage system. Where the two lines cross, a cement plug was installed capping the abandoned water main and we believe that the plug/cap is failing. This old water main was a main supply line for the entire area; therefore we believe that hundreds of thousands of gallons of water was left in the main and is now finding its way to our drainage system which has in turn overwhelmed the drainage system.
  • What may as well be an issue: On top of the abandoned water main, we also firmly believe that one of our major drainage ditches out in the marsh behind the airport is plugged. If that is indeed the case, this would back up our entire drainage system on Ocean Street, Plymouth Avenue, all roads off of Plymouth Avenue, Mayflower, Country Way, Surf Avenue as well as all the low lying streets off of Surf Avenue. Everything flows south toward the marsh therefore this issue of a blockage makes sense. Let’s not forget the amount of rainfall; that just compounds the problem.
  • What we have done thus far: To date all we have and could do is pump down the manholes in the system. We have also inserted a twelve inch rubber plug in the drainage line that intersects the old water main to try and slow down the flow of water coming into the system. We also did water sample tests to rule out a main break on our active water main. The PH levels were below our active water main levels so, this does rule out a main break.
  • What we are proposing to do: Foreman Jim Kent and I went to the airport this morning to see if we could gain access to the marsh and its ditch lines east of the airport and perhaps fly a drone over the area. Airport staff said they would assist us with anything we had to do. The airport also has their own drone and will fly it over the area to locate the blockage. For the time being; I am against digging up the area/road over the winter months unless it is extremely necessary. We will continue to pump when necessary, locate the blockage and remove it asap. If we can remove the blockage this will alleviate most of the flow that is backing up the system so we can repair the abandoned main issue without digging up the street.

I hope this sheds a little more light on what is going on and what we are up against. This has been a hot topic around town and I just wanted all of you in the loop if asked “what is going on?” If anyone has any questions please feel free ask. Thank you for your patience!

Shawn T Patterson

DPW Deputy Superintendent

Town of Marshfield, DPW