Monitoring & Testing

Manchaug Pond Foundation

An underwater swim in Manchaug Pond!

Manchaug Pond Foundation takes a multi-level approach to improving and protecting the water quality of Manchaug Pond and the watershed:

  • Monitoring & Testing in-lake and in the watershed
  • Education & Resources for Residents, Campers, Students and Hobby Farms
  • Roadside Structures installed to filter stormwater and capture non-point source pollution funded through the three EPA/DEP s.319 Nonpoint Pollution Grants.
  • Best Management Practices implemented on the Manchaug Pond Foundation owned 100 acre conservation property.

Clarity, Total Phosphorus, Temperature


Manchaug Pond Foundation Water QualityIn July 2015, a team of Manchaug Pond Foundation volunteers began a new effort to monitor the quality of our pond's water. For years, volunteers continue to work with the Blackstone River Coalition to monitor water quality at the pond's inlet, at the northwest cove, and outlet at the dam. And year's before that, the Manchaug Pond Association tested on-lake for clarity (Secchi Disc) and bacteria.

The team's focus is in-lake at the deepest location of Manchaug Pond.  The team records the data collected available for analyze over time.

To begin the effort, the water-quality team takes water samples at three different depths:

  1. to analyze total phosphorus
  2. to record water temperatures at 1-meter depth intervals
  3. and to measure water clarity using a Secchi disk.

In the future, the water sampling and analysis may extend to include chlorophyll, dissolved oxygen, and other measures of water quality.

IN-LAKE: Cyanobacteria, Phycoyanin & More

Absent or present? Non-detectable or is a bloom imminent? Latest results? -- click here.


The Worcester Cyanobacteria Monitoring Collaborative (WCMC) is a group of volunteer community scientists that tracks cyanobacteria activity at our local lakes and ponds. Between May and October, volunteers from Manchaug Pond Foundation and Stevens Pond collect samples 1-2 times a month and examine them under the microscope for cyanobacteria. In addition, the samples are analyzed using several other indicators of bloom risk. The WCMC is developing ways to assess risk to cyanotoxin
exposure using fast and low cost methods. These results are based on methods that are not certified by the Commonwealth of MA but are presented as recommendations so we can use to make informed choices about their contact.

The WCMC does not measure cyanotoxins, instead the group uses four parameters to determine the risk of cyanotoxin exposure. These include phycocyanin concentration, particle concentration, cyanobacteria density, and the cyanobacteria observed. Each of the results are ranked and given a color to identify severity. The overall risk of exposure at each lake is determined by reviewing all four parameters together.


  • Risk of Exposure: Overall risk of exposure to cyanotoxins in the waterbody based on a holistic interpretation of the data collected.
  • Phycocyanin: Cyanobacteria-specific pigment concentration in the water. The more phycocyanin there is in the water, the more cyanobacteria are present. However, because different kinds of cyanobacteria produce different quantities of phycocyanin, the risk of toxin production is different for the same concentration of
    phycocyanin when there are different cyanobacteria present.
  • Particle Concentration: Particles include living and non-living materials and can be a proxy for overall turbidity of the water. High concentrations of particles in the water can be indicative of cyanobacteria blooms, but can also be the result of other factors such as non-living debris and sediment. The phycocyanin concentrations and cyanobacteria density help to interpret if particles are due to cyanobacteria or other sources.
  • Cyanobacteria Density: The ratio of cyanobacteria to other organisms in the sample. Higher densities can indicate elevated risk of exposure to cyanotoxins. Density results do not consider concentration, but in general, systems dominated by cyanobacteria are at higher risk for producing toxins.
  • Cyanobacteria Observed: Genera of cyanobacteria identified in the sample. Because different cyanobacteria have different levels of phycocyanin, observed cyanobacteria help determine the threshold of phycocyanin that is considered risky.

WATERSHED: Coliform & Ecoli Bacteria


UPSTREAM, INLET & OUTLET: Nutrients, Oxygen & More

As part of the BLACKSTONE RIVER COALITION (BRC)Manchaug Pond Foundation Affiliations

The Blackstone River Coalition watershed-wide monitoring program tests monthly in three locations in the Manchaug Pond watershed from April through November as part of a watershed-wide Water Quality Monitoring Program for the Blackstone River system.

water quality

BRC's Interactive Map ~ Find Manchaug Pond on the Mumford River Tributary!

Manchaug Pond is part of the headwaters of the Mumford River which is a tributary of the Blackstone River watershed. The 75+ sampling sites are assessed for the following:

  • aesthetics:
    • water appearance
    • presence/non-presence of odor, trash, and nuisance aquatic vegetation
    • turbidity
  • water temperature
  • air temperature
  • dissolved oxygen saturation
  • dissolved oxygen
  • nutrients
    • orthophosphate
    • nitrate
  • conductivity

Go to Blackstone River Coalition's website for sampling results on their new interactive map of sites up and down the river, and other initiatives as part of the campaign to make the Blackstone River Fishable/Swimmable.  The years of data allows for long-term trends for the river system as well as analysis of sites and hotspots noting weather and stormwater events.

Public Swimming

Campground and the Y day camp waterfronts swim beaches are monitored weekly by each facility with results reported to the respective town's Board of Health and to the state. Click for more information...