WATER QUALITY SUMMARY

Little Sebago Lake, Windham

MIDAS: 3714, Sample Station # 1 (North)

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 datasets for Station # 1 of Little Sebago Lake have been collected since 1975. During this period, 7 years of basic chemical information was collected in addition to Secchi Disk Transparencies (SDT). In summary, the water quality at Station # 1 of Little Sebago Lake is considered average based on measures of SDT, total phosphorus (TP), and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Little Sebago Lake is low to moderate.

Water Quality Measures: Sample Station # 1 of Little Sebago Lake is considered colored (average color 40 SPU), while other Sample Stations have lower color values. The average SDT at Sample Station # 1 is 3.9 m (13.0 ft). The range of water column TP at Sample Station # 1 is 4-14 parts per billion (ppb) with an average of 10 ppb. Chla ranges from 1.8 - 6.7 ppb with an average of 4.0 ppb. Recent dissolved oxygen (DO) profiles show moderate DO depletion in deep areas at Sample Station # 1. The potential for phosphorus to leave the bottom sediments and become available to algae in the water column (internal loading) is moderate. Oxygen levels below 5 parts per million stresses certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species.

Little Sebago Lake has a population of an invasive aquatic plant, a hybrid species of variable milfoil (Myriophyllum heterophyllum x laxum). The Little Sebago Lake Association (LSLA) is working diligently to control this infestation and to prevent spread both of this plant to other lakes and of other invasive plant species to Little Sebago. More information is available at the LSLA website ( http://www.littlesebagolake.com/ ).

Sample Station # 2 (Middle)

Water quality monitoring datasets for Little Sebago Lake Sample Station # 2 has been collected since 1975. During this period, 3 years of basic chemical information was collected, in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Little Sebago Lake is considered to be slightly above average, based on measures of SDT, total phosphorus (TP), and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Little Sebago Lake is low.

Water Quality Measures: Little Sebago Lake Sample Station # 2 is a non-colored lake (average color 14 SPU) with an average SDT of 5.9m (19.5ft). The range of water column TP for Little Sebago Lake is 5-7 parts per billion (ppb), with an average of 6 ppb, while Chla ranges from 2.1-2.4 ppb with an average of 2.3 ppb. Recent dissolved oxygen (DO) profiles show slight 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. Oxygen levels below 5 parts per million stresses certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species.

Sample Station # 3 (deep hole)

Water quality monitoring datasets for Little Sebago Lake Sample Station # 3 have been collected since 1975. During this period, 11 years of basic chemical information was collected in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Little Sebago Lake is considered above average based on measures of SDT, total phosphorus (TP), and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Little Sebago Lake is low.

Water Quality Measures: Little Sebago Lake at Sample Station # 3 is non-colored with an average color of 15 SPU. (Note that the lake at Sample Station # 1 (North) is colored). Sample Station # 3 has an average SDT of 6.6 (21.7 ft). The range of water column TP for Little Sebago Lake at Sample Station # 3 is 5-16 parts per billion (ppb) with an average of 8 ppb. Chla ranges from 2.7-5.4 ppb with an average of 4.0 ppb. Recent dissolved oxygen (DO) profiles show low to 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 loading) is low. Oxygen levels below 5 parts per million stresses certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species.

Sample Station # 4 (South)

Water quality monitoring datasets for Little Sebago Lake Sample Station # 4 have been collected since 1977. During this period, 8 years of basic chemical information was collected in addition to Secchi Disk Transparencies (SDT). In summary, the water quality of Little Sebago Lake is considered slightly above average based on measures of SDT, total phosphorus (TP), and Chlorophyll-a (Chla). The potential for nuisance algal blooms on Little Sebago Lake is low to moderate.

Water Quality Measures: Little Sebago Lake at Sample Station # 4 is non-colored with an average color of 18 SPU (note: the lake at Sample Station # 1 in the north is considered colored). The average SDT at Sample Station # 4 (South) is 5.3 m (17.4 ft). The range of water column TP at Sample Station # 4 (South) is 6-17 parts per billion (ppb) with an average of 10 ppb. Chla ranges from 2.6-7.9 ppb with an average of 4.2 ppb. Recent dissolved oxygen (DO) profiles at Sample Station # 4 (South) show low to moderate DO depletion in deep areas. The potential for phosphorus to leave the bottom sediments and become available to algae in the water column (internal loading) is low. Oxygen levels below 5 parts per million stresses certain cold water fish, and a persistent loss of oxygen may eliminate or reduce habitat for sensitive cold water species.

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: Seba3714_01,02,03,04, Revised: 3/06, By: JM. Updated: 10/11, By: lal.