Stream Water Quality in Belmont
June 9, 2003
Libby Larson. Mystic Monitoring Network Coordinator
Mystic River Watershed Association
(adapted from a PowerPoint presentation)

• Volunteer water quality monitoring group run by the Mystic River Watershed Association
• Monitoring at Winn's Brook at Little Pond for almost 3 years
• Shorter, more intensive "hot spot" studies of Winn's Brook, Wellington Brook, and Alewife area.
• Primary focus on fecal coliform and E. coli bacteria:
  • MA Surface Water Quality Standards for 1° (200 cfu/100 ml) and 2° contact (1,000 cfu/100 ml)
  • Potential risk to public health

• Regular monthly monitoring at outfall to Little Pond (WIB001)
  • Recent E. coli results range from 380 cfu/100 ml in April 2003 to 6,900 cfu/100 ml in March 2003.
  • Highest recorded: 17,300 cfu/100 ml (fecal coliform) on wet weather event 5/22/01.
  • Approximately 75% of samples violate standard for 1° contact, 45% of samples violate standard for 2° contact.
• Hot Spot monitoring in March 2002
  • Results range from non-detect to 1,900 cfu/100 ml at N. side of Sherman St.
  • 2 locations violate standard for 1° and 2° contact: Sherman St. and WIB001.
  • 2 locations violate standard for 1° contact: Clifton St. at Hickory Lane and Howells Road Footpath.

• Generally lower results upstream, higher results downstream.
• Significant portions of Winn's Brook are culverted (underground).
• Possible sewage contamination in culverted sections.
• More sampling needed, especially during warm and wet weather.

• Hot spot monitoring in December 2001
  • Results range from 84 cfu/100 ml at NE corner of Claypit Pond to 65,000 cfu/100 ml at Common Street.
  • 78% of the samples violate standard for 1° and 2° contact (i.e. > 1,000 cfu/100 ml).
• Additional sampling during Alewife Brook studies (to be discussed later).

• Significant portions of Wellington Brook are culverted (underground).
• Possible sewage contamination in culverted sections.
• Generally higher results each time the brook surfaces.
• Cold air in open sections lowers bacteria levels.
• Settling of bacteria in Claypit and Perch Ponds lowers bacteria levels.
• More sampling needed, especially during warm and wet weather.

• Focus of hot spot monitoring due to Alewife Brook Variance, NPDES Permits for CSOs, CSO Control Plan, and related regulatory issues surrounding the area.
  • Several rounds of sampling:
  • December 2001 - centerline
  • April 2002 - pipes/tributaries
  • June 2002 - centerline and 5 pipes/tributaries
  • October 2002 - wet weather at 5 pipes/tributaries
  • November 2002 - wet weather centerline and 6 pipes/tribs
  • January 2003 - 4 pipes/tributaries
  • February 2003 - centerline and 9 pipes/tributaries
  • March 2003 - 5 pipes/tributaries
  • April 2003 - pipes/tributaries
• Pipes and Tributaries from Belmont:
  • At Little Pond: Spy Pond Conduit (BEL013) and Stormdrain in NW corner (BEL011)
  • Mass Highway Pipe from Rt. 2 (HWY001)
  • Drain from Acorn Park (ACORN1)
  • Stormdrains from Wellington Brook neighborhoods: CAMD33, CAMD34, BEL08X, BEL08S, BEL08N
  • Wellington Brook input to Perch Pond
  • Winn's Brook input to Little Pond
• Results:
  • Extremely high (>200,000 cfu/100 ml) results initially at NW Little Pond drain. Town of Belmont discovered collapsed sewer line and fixed, counts down to 4,700 cfu/100 ml (April 2003).
  • High results (9,600 cfu/100 ml) at Spy Pond Conduit in June 2002. Town of Belmont has done work here as well, results down to 44 cfu/100 ml in April 2003.
  • Very high (49,000 cfu/100 ml) at CAMD33 during wet weather of October 2002. Dry weather results still relatively high (10,3000 cfu/100 ml) in April 2003.
  • Very high (28,000 cfu/100 ml) at BEL08N during wet weather of October 2002). Dry weather results as low as 4 cfu/100 ml.
  • Continued high levels at Wellington Brook at Common St.
• Summary and Hypotheses
  • Although reduced by recent remediation work, Belmont contributes substantially high levels of bacteria to the Alewife system
  • Continued work and monitoring needed at NW corner of Little Pond
  • Need investigation into causes of high results at Wellington Brook
  • More sampling needed, especially during warm and wet weather at CAMD33, BEL08N, and WIB001.

• Most stretches Belmont's brooks are culverted and out of site, however the brooks do have areas of easy public access
• Culverted sections of Winn's and Wellington Brooks probably receive sewage contamination
• Belmont contributes significantly to the bacterial problems of the Alewife Brook sub-watershed
• Continued monitoring and remediation work is needed to bring Belmont's brooks into compliance with state and federal water quality standards.