Crystal Lake Conservancy's
2012 Water Analysis
by Janice Bourque, Co-President, Crystal Lake Conservancy
The Crystal Lake Conservancy's continuing
activities, carried out by our many dedicated
volunteers, include two major efforts:
- Monitoring water visibility and temperature
- Water sampling and laboratory analysis.
The Conservancy held its third Annual
Forum in October and presented the results
of the water analysis it conducted from May
2012 to October 2012. Those results
indicated that the health of Crystal Lake deteriorated over the past year. This article
will summarize those results and present
some solutions to the problems.
In full contrast to the situation in the summer
of 2011, Crystal Lake was under a great deal
of stress in 2012 and has entered a eutrophic
phase, as indicated by higher-than-average
water temperatures, increasingly low visibility,
low dissolved oxygen, increased presence of
nuisance aquatic plants (coontail appearing
abundantly in Cronin's Cove) with higher
bacteria, phosphorus and algae levels. Normal lake aging and eutrophication occurs over
centuries and results from natural sources of
nutrients and sediments. Crystal Lake, however,
is undergoing a "cultural eutrophication,"
whereby this natural process is accelerated by
the increased levels of bacteria and nutrients
that flow off a more densely developed
For the third year, volunteers recorded weekly
temperature and visibility readings at three
different depths (1 foot, 10 feet and 20-30 feet,
which is the bottom of the lake) at six specific
sites around Crystal Lake between May 2012
and October 2012. Water temperatures rose
rapidly from 40-50 degrees in the spring to
70-80 degrees in the summer and remained
fairly high and constant at all depths due to
unusually high ambient temperatures during
the summer. Water visibility was at 10 feet in
late May but rapidly declined to 0-2 feet by
the end of July; it then improved to 10 feet
at the end of August but had another rapid
decline to 0-2 feet visibility during the first week in September due to two large
algae blooms. The State Department of
Public Health closed the lake to public
swimming when water visibility was less
than 4 feet: lifeguards could not easily see
swimmers in the water, and algae counts
were high, which could expose residents
to potential toxins.
Trained volunteers also collected water samples to identify
factors affecting the overall health of the lake. Water samples
were taken during an actual heavy rainstorm and within
several hours of a rainfall or on the next day from six different
locations on eight different dates from April 26 until October
4, 2012, and were analyzed by a state-certified lab. The CLC
sampling methodology for water quality was consistent with
state protocol for swimming water quality. The testing focused
on Cronin's Cove, Levingston Cove, Lake Terrace, the center
of the lake, the public swimming area and the outflow into
Paul's Brook by the railroad tracks. The comprehensive tests
included bacterial analysis (E. coli and Enterococcus),
herbicides, pesticides and fertilizer components such as nitrate,
ammonia, and phosphorus. Beals Associates conducted deepwater
temperature, phosphorus and dissolved oxygen testing
in August during the algae bloom. (Dissolved oxygen indicates
the amount of oxygen in the water to sustain animal life.)
- The results of CLC's sampling were as follows:
- Bacterial test results were variable depending on location
and date. Five dates revealed bacteria levels well below the
Maximum Contaminant Limits (MCL). However, three
testing dates showed E.coli and Enterococci levels well
above the MCL in Levingston Cove, Cronin's Cove, and
- No herbicides or pesticides were detected.
- Nitrate results were low and typically below detection limits
- Phosphorus was detected early in the season in the deep
water and at Cronin's Cove. The deep-water detection was
of particular concern given the opportunity for normal
dilution as the water flows from the outfalls to the center
of the Lake. Beals Associates' additional test results also
showed increased phosphorus elevations in deep water.
- Average phosphorus levels are 10 parts per billion (ppb).
Crystal Lake had phosphorus levels of 50-110 ppb.
- Dissolved oxygen levels began to drop when measured at
a depth of 10 feet, with rapid decline to zero oxygen at
25 feet. Animal life would have a difficult time surviving
at zero to no oxygen at these lower levels. Oddly, there
was no indication of a fish kill during the testing period.
So what have we learned?
Data on phosphorus levels indicates high levels are present
with a rapid increase over last year. High phosphorus is
related to algae blooms, and the real source is unknown.
We do know from the City of Newton's testing that there
are high levels of phosphorus present at street-level prior
to entering storm drains. Phosphorus is also distributed
differently than bacteria and settles to deeper levels, where
it easily can be stirred up again when the lake is disturbed
or when it naturally turns over in the spring and fall.
2. Bacteria are present and high in some areas.
Bacteria data has been consistent now for several years,
with increased occurrences of higher levels in areas that
have less current movement, such as in Cronin's Cove,
Levingston Cove, and Lake Terrace. It is unpredictable
when higher levels occur, and the direct source is
unknown. Testing performed by the City of Newton has
revealed that very high levels of bacteria are known to
exist in street runoff PRIOR to its entering storm drains.
This suggests the issue is in the watershed area, and the
main source may not be any material found in the storm
drains. Despite some high bacteria levels, there is rapid
dilution of the bacteria to low levels as the flush from the
streets moves toward the center of the lake.
What can the watershed residents do to help decrease
the amount of pollution flowing into Crystal Lake?
- Decrease the amount of nutrients (fertilizer, pesticides,
compost) used in our yards that then flow onto adjacent
streets and into the lake.
- Reduce the amount of bacterial flow occurring on street
level in yards, driveways and streets. Do not dump waste
- Reduce stormwater and gutter runoff by allowing it to
infiltrate into soil; manage waterfowl; and reduce any
- Voluntary compliance is very important. If the situation
does not improve, concerned residents might decide to
explore creating new City regulations as a last resort.
What can the City of Newton do?
1. Continue to investigate the storm drains and
sewer lines and do regular cleaning out.
Leakage from sewer systems can cause sludge and
detergents to leak into groundwater supplies, increasing
phosphorus load. The City has done substantial work to
investigate and insure the patency of lines.
2. Investigate methods of draining street water into
natural filtration areas before it runs into storm
drains: create sustainable drainage.
Redirect storm drains to catch basins, retention basins,
and detention tanks that won't drain directly to lake.
The City could also explore improved drainage
systems-swales, bioswales, and permeable paving.
3. Explore alternative in-lake restoration techniques
The following measures involve more cost and time,
can have negative side effects, and can be avoided if
resources were put into finding and addressing the real
source of pollution:
Through hypolimnetic aeration, oxygen could be
pumped into the lowest level in the lake and could
provide more dissolved oxygen to animal life. Artificial
circulation (fountains, paddlewheels, air diffusers) such
as used in the bathhouse area could provide aeration to
expose the lake water to more oxygen and could be
added to the various Coves. Through hypolimnetic
withdrawal, siphons could be used to remove nutrient
rich water, which then would be replaced by neutral water.
Dilution methods could flush the lake to reduce algae
but would require lots of water. Nutrient diversion techniques could utilize expensive engineering to
divert drains. Dredging could use heavy hydraulic
equipment to increase the depth of the lake and could
remove sediment; it was used for Bullough's Pond.
Nutrient inactivation could also be performed
utilizing aluminum, iron, or calcium salts to inactivate
phosphorus. Alum treatment (aluminum sulfate) can last
eight or more years but also can have deleterious effects
on the living creatures in the lake.
It is incumbent upon all of us to slow the accelerated
eutrophication of Crystal Lake in order to keep it healthy
for years to come. For more information on Crystal Lake
and the work of the Conservancy, visit