Who is responsible to clear snowy sidewalks around the ENTIRE town of Westford?

First off, I want to say the Westford DPW does an overall great job of keeping the streets safe and clear of snow and ice during winter storms.  

My blog point is to ask who is responsible for clearing the sidewalks in and around the entire town of Westford?  I do my best and part of clearing my driveway and a 'widemouth' at the end of the driveway.  I also have a fire hydrant close to my home that I shovel out routinely.  My street does not have any sidewalks (it is a dead end street) but there are plenty of sidewalks in my area (Graniteville and Forge) that are now completely covered and will not be cleared until nature says so (if you catch my snowdrift?).  

I have seen alot of people walking (the dog) and jogging the now narrower streets of Westford.  I know alot of kids walk to school and walk to their bus stops using the town sidewalks too.  Obvioulsy there is a significant safety issue without having safe sidewalks for everyone to use.  During my commute to Boston, Concord's Lowell Road sidewalks were completely clear.  I saw the same in Littleton yesterday along Goldsmith Street.  I have not traveled other streets in and around Concord and Littleton like I do in Westford, but most of the sidewalks around town seem to be completely covered still.  Granted, I am one who says stay in, walk in your own neighborhood (not main streets) or goto the gym versus putting yourself and drivers in danger.  This is an annual and important safety issue that never seems to get answered.  Does anyone know?  

PS I believe I have heard that the sidewalks around the Common get done by the town because they are 'the most important'.  That would not sit well with me, at all!  In today's day and age of email, faxes and use of computers there is no document that 'Nancy' at Ex: Town Hall couldn't scan, fax or email to ex: the WFD.  Aren't the tax paying neighbors and kids lives in Nab, Forge and GVille important too?