WATER QUALITY SUMMARY

Unity (Lake Winnecook) Pond, Unity and Burnham

MIDAS: 5172, Sample Station # 1

The Maine Department of Environmental Protection (Maine DEP) and the Volunteer Lake Monitoring Program (VLMP) have collaborated in the collection of Unity Pond data to evaluate water quality, track algal blooms, and determine historical water quality trends. This dataset does not include bacteria, mercury, or nutrients other than total phosphorus.

Water quality monitoring datasets for Unity Pond have been collected since 1977. During this period, 19 years of basic chemical information was collected in addition to 29 years of Secchi Disk Transparency (SDT) readings. In summary, the water quality of Unity Pond is considered poor based on measures of SDT, total phosphorus (TP), and chlorophyll-a (Chla). The potential for nuisance summertime algal blooms on Unity Pond is high.

Water Quality Measures: Unity Pond is a lightly colored lake (average color 36 SPU) with an average SDT of 2.4 meters (7.9 feet). The range of upper water column TP for Unity Pond is 12 - 30 parts per billion (ppb) with an average of 21 ppb. Chla ranges from 2.9 - 41.0 ppb with an average of 16.4 ppb. The potential for phosphorus to leave the bottom sediments and become available to algae in the water column (internal loading) is moderate to high. Recent dissolved oxygen (DO) profiles show moderate DO depletion in deep areas of Unity Pond.

Comments: Unity Pond is on the state listing of Maine lakes in non-attainment of water quality standards due to excessive total phosphorus loadings from the surrounding watershed.

Nutrient Management: A Unity Pond combined Phosphorus Control Action Plan (PCAP) and Total Maximum Daily (Annual Phosphorus) Load (TMDL) report was prepared by Maine DEP during 2001 - 2004, with assistance from Unity College and the Maine Association of Conservation Districts (MACD) project team. Following lake stakeholder and public reviews, this document was approved by US-Environmental Protection Agency (EPA) (New England) on September 16, 2004. This final report, along with the EPA-New England review summary and letter of approval, can be found on the Maine DEP webpage at: http://www.maine.gov/dep/water/monitoring/tmdl/tmdl2.html .

See the Maine DEP Explanation of Lake Water Quality Monitoring Report for measured variable explanations. Additional lake information can be obtained by contacting Maine DEP at 207-287-3901 or VLMP at 207-783-7733, and at these Websites: http://www.lakesofmaine.org and http://www.maine.gov/dep/water/lakes/index.html and http://www.mainevolunteerlakemonitors.org .

Filename: Unity5172.doc, revised: 03/2005, by dbh. Updated: 10/11, by lal.