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Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Controlling Erosion Helps Restore Echo Lake
M (line-
Waterbody Improved
Echo Lake's water quality began to decline in the late 1960s.
Stormwater runoff carried phosphorus-laden soil from
the watershed's potato cropland, roads, and residential areas and deposited it in the lake.
In-lake phosphorus levels increased, eventually leading to persistent annual algal blooms and
occasional fish kills. As a result, in 1986 the Maine Department of Environmental Protection
(DEP) added Echo Lake to the state's Clean Water Act (CWA) section 303(d) list of impaired
waters. From 2003 to 2007, DEP and the Central Aroostook Soil and Water Conservation
District helped landowners install sediment and erosion control best management practices
(BMPs) at high-priority sites. Installing the BMPs, combined with a substantial decline in
active cropland in the watershed, reduced the sediment and phosphorus loads entering the
lake. Water quality improved and now meets the state's water quality standards, prompting
DEP to remove Echo Lake from the state's list of impaired waters in 2012.
Problem
Echo Lake is in the city of Presque Isle in northern
Maine (Figure 1). Created in 1864 by the damming
of Arnold Brook, the 90-acre lake has a drainage
area of 936 acres (1.5 square miles). Land use within
the watershed is 41 percent undeveloped, 33 per-
cent forest, 9 percent surface water, 9 percent
agriculture, 4 percent non-shoreline development,
and 4 percent shoreline development. A portion
of the lake is in Aroostook State Park (Maine's first
state park), which draws as many as 16,000 to
19,000 people to the area every year to enjoy camp-
ing, boating, and other activities.
Echo Lake's vulnerability to water quality problems is
due in part to the lake's shallow depth—
a maximum depth of 9 feet and a mean depth of
5 feet—and its nutrient-rich sediments, as well as
the watershed's highly erodible soils. Beginning in
the 1960s, the considerable amount of agricultural
land (potato cropland) in production, combined with
an increasing number of roads and homes along
the lake's shoreline, gave rise to poor water quality.
Between 1965 and 1975, local residents noticed
changes in the water quality of Echo Lake, includ-
ing noxious smells, turbid water, algal blooms, and
occasional fish kills. DEP and the Maine Volunteer
Lake Monitoring Program began regular water
quality monitoring in 1976. DEP collected five lake
water chemistry samples in the 1970s and 1980s,
all of which showed elevated phosphorus levels
(two grab samples: 19 and 35 parts per billion [ppb];
higure 1. Echo Lake is in northern Maine
three epilimnion core samples: 19, 21, and 41 ppb).
In 1986 DEP added Echo Lake to Maine's CWA sec-
t on 303(d) list of impaired waters for nuisance algal
blooms.
Nutrient contamination, which gives rise to algal
blooms, is due in large part to nonpoint source
inputs of phosphorus from eroding soils. An Echo
Lake watershed survey completed in 2001 docu-
mented 315 eroding sites; of these, 66 percent
were in residential areas, 24 percent were associ-
ated with state parkland, and 7 percent were along

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municipal roads. In 2007 DEP developed a total
maximum daily load (TMDL) for phosphorus in Echo
Lake. The TMDL estimated that 136 kilograms (kg)
of phosphorus was exported annually from the
watershed into Echo Lake, and that this amount
would need to be reduced by 42 kg annually to
meet the numeric (in-lake) water quality target of
15 ppb total phosphorus. Meeting that target would,
in turn, allow the lake to comply with Maine's nar-
rative water quality standard, which requires that
lakes have a stable or decreasing trophic state and
be free of culturally induced algal blooms.
Project Highlights
From 2004 to 2007, stakeholders installed erosion
and sediment control BMPs at 60 percent of the
high-priority erosion sites documented in the 2001
watershed survey. The BMPs were installed on five
town roads, 19 residential lots, two private roads,
and four state park sites. The city of Presque Isle
improved gravel-surface roads by reestablishing
and stabilizing road ditches; adding ditch turnouts
to buffers; and installing new cross-drain culverts,
plunge pools, and road surface crowning. BMPs
installed in Aroostook State Park included stabilizing
an eroding embankment, grading and resurfacing
the main parking area with non-erodible permeable
aggregate, installing water bars (a ridge of material,
like a speed bump, that runs diagonally to divert
stormwater into a stabilized area) on campground
roads and foot trails, and grading and resurfacing a
boat landing.
The phosphorus and sediment that had previously
contributed to Echo Lake's algal blooms were also
reduced through a gradual reduction in agricultural
cropland throughout the watershed. Over the past
20 years, the amount of acreage involved in farming
in the watershed has declined from approximately
70 acres (8 percent of the watershed) to 20 acres
(2 percent of the watershed).
Results
After gradual improvement, the lake now meets
Maine's lake water quality standards. The lake has
a stable or decreasing (improving) trophic state and
has been free of culturally induced algal blooms for at
least six of the last 10 years (Figure 2). Algal blooms
are considered to have occurred when the annual
minimum Secchi disk transparency falls below 2
meters. The CWA section 319-funded project reduced
the annual sediment load to Echo Lake by 30.5 tons
Annual Minimum Secchi DiskTransparency
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Figure 2. Annual minimum Secchi disk transparency.
per year and reduced the phosphorus load by 30
pounds per year. From the 1990s to the present,
total phosphorus has decreased, ranging from 13 to
24 ppb for epilimnion core samples and 12 to 19 ppb
for surface grab samples. In 2012 DEP removed Echo
Lake from Maine's CWA section 303(d) list of impaired
waters. Despite the improvements, the lake is consid-
ered vulnerable to future phosphorus inputs and will
continue to be watched closely.
Partners and Funding
The Central Aroostook Soil and Water Conservation
District coordinated work to reduce sediment
and erosion from town roads, the state park,
and residential lands. Key project partners
included the city of Presque Isle, Aroostook State
Park, the Echo Lake Improvement Association,
the U.S. Department of Agriculture's Natural
Resources Conservation Service (NRCS), the
Maine Department of Agriculture (MDOA), DEP,
and the U.S. Environmental Protection Agency
(USEPA). USEPA provided $54,000 in CWA section
319 funds, and MDOA provided $18,000 in state
grant funds. The NRCS Central Aroostook Office
provided technical assistance, including surveying
and designing BMPs. Presque Isle donated labor
and equipment valued at $18,463 to address road-
related erosion problems. The Maine Department
of Conservation-Aroostook State Park invested
$21,400 to address erosion-related issues during
the CWA section 319 project. Two private road
associations invested $7,935 to install road-related
erosion control BMPs.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-14-001F
January 2014
For additional information contact:
Kathy Hoppe
Maine Department of Environmental Protection
207-540-3134 • Kathy.M.Hoppe@Maine.gov

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