Water Quality Monitoring


Once a month, early on a Sunday morning, citizen scientists head out to sites along the Assabet, Sudbury, and Concord Rivers to collect water samples, measure pH, temperature and record river conditions. The data and analyses enable OARS, municipalities, environmental agencies, and others to improve management of our waterways.

Volunteers are fully trained by OARS staff and all equipment is provided. Training dates for new and returning volunteers:

  • Sunday, May 5th, 8:30am in Acton
  • Wednesday, May 8th, 7:00pm in Hudson
  • Saturday, May 11th, 8:30am in Wayland at the Rt. 20 boat launch
  • directions to all sites

This is your chance to make a real difference. Join our group of dedicated citizen scientists working to monitor and improve the water quality of our three rivers and their tributaries. To volunteer please email us

The 2019 sampling season starts in May. We sample on Sunday mornings (dates below). Sampling generally starts at 5:30 am and takes about three hours. You can sign up to help on all six Sundays or as few as three. Teams of 3 volunteers each sample one section of the rivers (4 - 6 sites):

  • Assabet River, Westborough to Marlborough
  • Assabet River, Berlin to Hudson
  • Assabet River, Acton to Concord
  • Sudbury River, Framingham to Concord
  • Concord River, Concord to Lowell

Sampling dates:
Sunday, May 19th (start 5:30am)
Sunday, June 16th (start 5:30am)
Sunday, July 14th (start 5:30am) tentative
Sunday, August 11th(start 5:30am)
Sunday, September 22nd (start 6:30am) tentative
Sunday, November 10th (start 8:00am)

More information about OARS' water quality monitoring program.