A few months back the main sewer line leaving the town collapsed resulting in a severe back up that filled the nearby savings bank and restaurant on Cambridge Street with raw sewerage several feet deep. The result was that both operations were closed for an extended period of time. In the case of the restaurant it was several months. The damage done was beyond the closed period because in the restaurants case how could you go into restaurant and not have a thought as to just how deep the sewerage was in the building? Some how the vision is not that appetizing.
This event happened during a very rainy period which also resulted in surcharging in the Vine brook in order to relieve the down stream pressure. The state had issued an emergency and the town was re-imbursed for some of the cost of the disaster but a question remains as to whether this was a preventable occurrence.
This particular exit line begins as a forced main under pumping pressure at the Terrace Hall pumping station. It then goes directly through the Great Meadow well fields and up Mall Road. It takes a right hand turn at South Bedford Street and then a left hand turn down Wayside Road to Cambridge Street.
History told us that this line was going to fail further in the area where it did. Previously there had been a failure on South Bedford Street and then another several years later further down at Wayside Road. Apparently what happens is that the sewer gases which are created in the line eat away the cement pipes causing the ultimate failure and cave in. The town responds to this by repairing the line and then putting a vinyl type insert into the line which is impervious to the corrosive effect of the sewer gas. Each time it happens the town for financially short sighted reasons only extends the vinyl insert a few hundred feet beyond the latest fault point.
Given this history let me be bold and make a prediction that the next catastrophic failure will happen a few hundred feet beyond the end of the latest vinyl insert. That should put the exact location somewhere between Ray Avenue and the Burlington Woburn town line.
If I were a business or home in that area I would be calling the Selectmen right now to make sure that camera inspections are being done to determine the exact condition of that sewer line.
From a simply cynical and skin flint point of view it makes some sense not to spend the extra money for preventative action by vinyl lining all of the rest of the pipe if there is a slight chance that we won't experience another similar type failure. Personally I think that is a short sighted attitude. If something has happened three times along a predictable path then why not save the money and aggravation and take care of the whole problem now?
An isolated case of broken sewer main creates a miserable event for those affected but does not even show up on the radar screen for the rest of us. In this case it was in the papers a couple of days and some wondered why the two businesses were closed but for the most part the event went unnoticed town wide.
There is an element to this however that everyone ought to be concerned about. The front part of this line which extends back to the Terrace Hall station cuts the Great Meadow well field almost in half. This area is responsible for approximately 40% of the town's water production. Since the line is almost 50 years old it is just as susceptible to the twin elements of age and corrosion as the part of the line that has already collapsed.
If the line fails in the well field and leaks for an extended period of time what are the implications for water quality and the long term health of the well field? How long would production be affected? What is the cost of a potential repair versus replacing the line completely?
There has been some talk of replacing this line however no appropriations have appeared at town meeting to accomplish this. At the very least the town ought to take action to both test the surrounding ground water as well as somehow manage to camera inspect this line. Although it is under pressure there should be methods available and time enough late at night to allow for a camera to get in there and survey the whole length of the pipe.
The DPW has done an excellent job of preventative maintenance and responding to emergencies however this is a policy and a financial decision that requires action by the executive and legislative branches of town government. Three seperate failures should be sufficient warning to all of us.
