WATER QUALITY SUMMARY

HERMON Pond, Hermon

MIDAS: 2286, Sample Station # 1

The Maine Department of Environmental Protection (Maine DEP) and the Volunteer Lake Monitoring Program (Maine VLMP) have collaborated in the collection of lake 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 Hermon Pond have been collected since 1980. During this period, 9 years of basic chemical information was collected along with 24 years of Secchi Disk Transparency (SDT) measures (continuous from 1984-92 and 1998-2010, no records for 1993-97). In summary, the water quality of Hermon Pond is considered below average based on measures of SDT, total phosphorus (TP), and chlorophyll-a (Chla). The potential for nuisance summertime algal blooms on Hermon Pond is high.

Water Quality Measures: Hermon Pond is a very colored lake (average color 73 SPU) with an average SDT of only 2.2 meters (7.2 feet). The range of upper water column TP for Hermon Pond is 7 to 48 parts per billion (ppb) with an average of 31 ppb. Chla ranges from 3.4 to 60 ppb with an average of 22.7 ppb. Recent dissolved oxygen (DO) profiles show moderate DO depletion in deep areas of the lake. The potential for phosphorus to leave the bottom sediments and become available to algae in the water column (internal recycling) is moderate.

Comments: Hermon Pond is managed by Maine Department of Inland Fisheries and Wildlife (MDIFW) (Region B) as a warm-water fishery. Hermon Pond frequently has annual nuisance (summertime) blue-green algal blooms which cause the pond to appear very green. The pond is considered safe to swim during the bloom, though many individuals prefer not to. Hermon Pond drains a very large wetland complex.

Nutrient Management: Hermon (and downstream Hammond) Pond has historically been listed on the Maine DEP/EPA 303(d) list of waters non-attaining Maine state water quality standards. A Phosphorus Control Action Plan (PCAP) and TMDL study/report was completed during 2005-06, however was not submitted to EPA. Recent paleolimnological (sediment diatom) studies have shown that Hermon (and Hammond) pond are “naturally” eutrophic (fertile) waters and they are now in the process of being removed from the 303(d) listing of TMDL waters and reclassified in the 2012 305 (b) state water quality report. The draft Hermon Pond PCAP can still be used as guidance for the implementation of recommended best management practices to help reduce total phosphorus loads from shoreline nonpoint pollution sources. The 2006 report can be found on the following Maine DEP webpage: 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: herm2286, Revised: 03/2006, By: dbh. Updated 09/2011, By: lal.