Fight it - it's NOT a violation according to the city's own guidelines as published on their webpage:
http://www.somervillema.gov/spotlight.cfm?id=7
* While stored on your property, all trash must now be held in a waterproof & airtight container with a lid. * Trash put out for pickup must remain in a container, but does not need to be covered. We encourage residents to remove lids before bringing trash to the curb in order to prevent loss or damage. * Trash storage containers may not exceed 50 lbs when full. * Times you may put out your trash remain the same: trash may be placed out for pickup no earlier than 4:00 p.m. on the day before trash collection and no later than 7:00 a.m. the day of trash collection.
Hell, from the brochure (http://www.somervillema.gov/CoS_Content/documents/Trash%20Brochurefinal.pdf):
Do I need to keep the barrel covered when I place it out for collection? No. We encourage you to remove the lids prior to placing your barrels out for collection.
only applicable if it was placed at the curb for pick up:
http://www.somervillema.gov/spotlight.cfm?id=7
* While stored on your property, all trash must now be held in a waterproof & airtight container with a lid.
* Trash put out for pickup must remain in a container, but does not need to be covered. We encourage residents to remove lids before bringing trash to the curb in order to prevent loss or damage.
* Trash storage containers may not exceed 50 lbs when full.
* Times you may put out your trash remain the same: trash may be placed out for pickup no earlier than 4:00 p.m. on the day before trash collection and no later than 7:00 a.m. the day of trash collection.
Hell, from the brochure (http://www.somervillema.gov/CoS_Content/documents/Trash%20Brochurefinal.pdf):
Do I need to keep the barrel covered when I
place it out for collection?
No. We encourage you to remove the
lids prior to placing your barrels out
for collection.