WATER QUALITY SUMMARY

LITTLE OSSIPEE FLOWAGE (LAKE ARROWHEAD), WATERBORO

MIDAS: 9715 Sample Station #1 (deep hole)

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

Water quality monitoring of Lake Arrowhead Sample Station #1 started in 1999. During this period, 1 year of basic chemical information was collected, in addition to 6 years of Secchi Disk Transparencies (SDT). In summary, the water quality of Lake Arrowhead is considered to be below average, based on measures of SDT, total phosphorus (TP) and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Lake Arrowhead is low.

Water Quality Measures: Lake Arrowhead Sample Station #1 is a moderately colored lake (average color 42 SPU) with and average SDT of 3.8 m (12.5 ft). The water column TP for Lake Arrowhead is 9 parts per billion (ppb) while Chla is 3.1 ppb. The only dissolved oxygen (DO) profile - taken in 2001 - shows little DO depletion in deep areas of the lake. The potential for TP to leave the bottom sediments and become available to algae in the water column (internal loading) is low. Lake Arrowhead is managed by the Maine Department of Inland Fish and Wildlife as a warm-water fishery.

Lake Arrowhead is one of the few lakes in Maine that is licensed for hydropower generation. The invasive aquatic plant variable-leaf milfoil is found throughout the lake. The local association has been conducting Courtesy Boat Inspections for 4 years and works to manage the spread of variable-leaf milfoil within the lake.

Sample Station # 2

Water quality monitoring of Lake Arrowhead started in 1999. Since no chemical data at sample station 2 has been taken, water quality is based on Secchi Disk Transparencies (SDT). In summary, the water quality of Lake Arrowhead is considered to be below average. The potential for nuisance algal blooms on Lake Arrowhead is probably low.

Water Quality Measures: Lake Arrowhead, sample station # 2, has an average SDT of 3.6m (11.8 ft). This is below the state average. Station 1 has moderate color thus station 2 is likely to have moderate color as well. Color does interfere with transparency readings. Total phosphorus and Chla levels recorded at Station 1 do not indicate that there is a high risk of algal blooms in the lake.

Lake Arrowhead is one of the few lakes in Southern Maine that is licensed for hydropower generation. The invasive aquatic plant variable-leaf milfoil is found throughout the lake.

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: oss97151, Revised: 12/06, by: kah