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NONPOINT SOIREE SICEESS STORY
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Wetland Enhancements and In-Lake freatments Restore Aquatic Life
Uses at Kezar Lake
t a I r ^ j	I In the 1960s Kezar Lake experienced elevated levels of nutrients, which
¦	' P '	led to algal blooms and a large-scale fish kill. In 1980 local stakeholders,
the state of New Hampshire, and the U.S. Environmental Protection Agency (EPA) began addressing the poor quality
in Kezar Lake. Although the New Hampshire Department of Environmental Services (NHDES) had long been aware
of Kezar Lake's problems, the methodology to assess chlorophyll-o (chl-o) and total phosphorus (TP) levels for
designated use support were not developed until 2009. Based upon the assessment using that methodology, NHDES
placed Kezar Lake on the 2010 Clean Water Act (CWA) section 303(d) list of impaired waters for chl-o and TP. After
years-long and multiphase restoration efforts, including detailed analyses and monitoring, wetland enhancement, and
implementation of in-lake treatments, Kezar Lake has improved. It was removed from New Hampshire's 2012 CWA
section 303(d) list for its aquatic life use impairment due to satisfactory chl-o and TP concentrations.
Problem
Kezar Lake is a 182-acre lake in Sutton, New
Hampshire. The lake's maximum depth is 27 feet, and
the mean depth is 9 feet (NHLAK700030303-03-01).
The 6,848-acre watershed is mostly forested, but also
includes the 1-89 highway corridor, residential develop-
ment and agricultural lands. In 1934 Kezar Lake was
chosen as the location for Wadleigh State Park due to
the lake's beauty and recreational value.
In 1931 the town of New London constructed a
wastewater treatment plant that discharged treated,
but high-nutrient, effluent to Lyon Brook, which is
upstream of Kezar Lake. Algal blooms (Cyanophyceae)
began to plague Kezar Lake in 1963 (Figure 1). Initially
the concerns with this condition centered on aesthet-
ics and recreational opportunities. Five years later,
following continued blooms and a massive fish kill,
lake-shore property values around Kezar Lake dropped
significantly (1968 Sutton Town Report). Throughout
the 1960s and early 1970s NHDES applied nearly
3 tons of copper sulfate to Kezar Lake and performed
mechanical destratification by pumping compressed
air to the bottom of the lake in an attempt to reduce
the elevated phosphorus concentrations and stop
the algae blooms. The success of these efforts was
short-lived, however, and eventually proved to be
ineffective because of the resistance of the dominant
genus of Aphanizomenon holsaticum to copper sulfate
treatments.
Figure 1. Alga! blooms, such as this one in Kezar Lake in
1963, prompted restoration efforts.
In 1978 a CWA section 314 iake classification study
determined that Kezar Lake was a high priority for
restoration, which led to a 19-year, three-phase lake
restoration project, in 1983 NHDES completed a
Diagnostic and Feasibility (D&F) study, which evalu-
ated numerous criteria at 12 stations around the lake,
and documented elevated nutrient levels and internal
phosphorus loading from sediments contaminated
by years of wastewater treatment plant effluent.
Although the treatment plant was decommissioned in
1981, algae blooms persisted in Kezar Lake. Although
already listed as impaired for dissolved oxygen satura-
tion, Kezar Lake appeared on the 2010 CWA section
303(d) list of impaired waters for aquatic life use via
the newly established TP and chl-o indicators.

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Chlorophyll-o and Total
Phosphorus in Kezar Lake
Median Concentrations by Year
	mesotrophic
w 30-
5-1974,
destratification
1969,	WWTF
algae polishing
ponds added
1970,	WWTF
alum treatment
added
1981, WWTF
5 10
1984, aluminum
salts, sediment
deactivation
Year
Figure 2. Chlorophyll-o and total phosphorus
concentrations in Kezar Lake have declined over time.
Project Highlights
Remediation efforts began during the second phase
of the project, which involved implementing strate-
gies identified in the D&F study. Two main approaches
were employed to reduce phosphorus concentrations
in the lake. First, in 1983, NHDES installed flashboards
to elevate the water level in the Chadwick Meadows
wetlands, which allowed for Increased precipitation
of suspended particulates that transport phosphorus.
That same year, the Kezar Lake Protective Association
joined the New Hampshire Volunteer Lake Assessment
Program (VLAP), which is a program offered by NHDES
that provides training, annual lake visits by NHDES
biologists, equipment, and analyses of lake and tribu-
tary samples collected. Second, in 1984, aluminum
salts were injected into 100 acres of the lake bottom
to bind the available phosphorus. The aluminum
forms insoluble precipitates with phosphorus, thereby
removing the phosphorus from the water column and
depositing it in the sediment in forms unusable by
algae. In 1985 the wetland was further enhanced by
the planting of wild rice, which was chosen for its high
phosphorus attenuation potential.
To measure changes in the lake's condition, NHDES
established a water quality monitoring program from
1984 through 1988. Monitoring was conducted, in
part, through a CWA section 314 EPA grant for a res-
toration/protection project. To determine the success
of the restoration strategies, NHDES evaluated many
parameters, including water chemistry, sediment com-
position, fish tissue analyses and macroinvertebrate
communities.
Figure 3. Kezar Lake water quality has improved.
Results
The thresholds established for a mesotrophic lake are
5 micrograms per liter (|ig/L) for chl-o and 12 |ig/L
total phosphorus. Before restoration efforts, chl-o
values were as high as 50 |ig/L, and TP values were as
high as 57 |ag/L. The median values calculated for the
2012 assessment are 4.5 |ig/L chl-o and 12 |ig/LTP.
Annual VLAP monitoring data indicate that chl-o is still
on an improving trend, and TP is stable and meeting
standards (Figure 2). Although dissolved oxygen satu-
ration and pH are still not supporting designated uses,
and chloride measures are trending higher (likely due
to road salt), the restoration efforts at Kezar Lake have
proven to be successful In reducing TP concentrations
and the occurrence of algal blooms (Figure 3). Because
of these efforts Kezar Lake transitioned from eutrophic
to mesotrophic between 1978 and 1984 and aquatic
life use is no longer impaired by chl-o and TP. As a
result, these impairments were removed from NH's
2012 CWA section 303(d) list.
Partners and Funding
This project involved cooperation of the Kezar Lake
Protective Association, the town of Sutton, the New
Hampshire Fish and Game Department, Jody Connor
and the NHDES Watershed Management Bureau, and
EPA. The association of local volunteers, along with
town, state, and federal staff worked cooperatively
throughout the project period. EPA provided signifi-
cant support for this project by funding the initial D&F
study, providing partial funding for the restoration
implementation phase, and through a $121,577 CWA
section 314 grant for the post-implementation Phase
III analysis. Additionally, in-kind services and assistance
of staff, equipment and other resources have been
provided by NHDES programs which are supported
by CWA section 319 grant funds. The Kezar Lake
Protective Association, in cooperation with NHDES,
continues to provide additional funding and in-kind
services through volunteer monitoring activities.
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U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA 841-F-17-001B
January 2017
For additional information contact:
Jeffrey Marcoux, Watershed Supervisor
New Hampshire Department of Environmental Services
603- 271-8862 • jeffrey.marcoux@des.nh.gov
Erik H. Beck, Environmental Protection Specialist
U.S. Environmental Protection Agency, New England Region
617-918-1606 • beck.erik@epa.gov

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