The "Green" State of Crystal Lake
and What You Need to Know
By Maria Rose, Environment Engineer, City of Newton
the ideal conditions
to enjoy our local
parks, beaches and
but this summer the
at Crystal Lake were
less than ideal. If you
were here in early
August 2012, then you
probably noticed the
bright green color
of the lake water. If
you'd like to know
what happened and
why, then read on.
A widespread bluegreen
swimming ban at
Crystal Lake for
much of August.
The blue-green algae,
also known as
cyanobacteria, appear like thick green paint
on the lake's surface.
sunny weather and slow moving water provide
ideal conditions for algae blooms. With last
season's mild winter and a hot, relatively dry
summer, the stage was set for an early algae
bloom. Crystal Lake often experiences a latesummer
algae bloom. Algae are mostly
microscopic plants that may be free-floating
(phytoplankton) or attached to a substrate
(periphyton). "In a moderately rich lake, there
could be nearly one hundred species of algae
in a tablespoonful of lake water. In a eutrophic
lake, there may be millions of cells in a gallon
of water." (The Practical Guide to Lake
Management, Massachusetts Department of
and the Department
of Conservation and
Based upon regional
information and data
we have gathered
about Crystal Lake,
it is a moderately
(nutrient) rich lake.
However, if warmer
winters and significant
continue, the lake will
Eutrophication is the
process by which a
body of water acquires
high concentrations of
nutrients (in particular,
algae growth. As
the algae die and decompose, high levels of
organic matter deplete the water of oxygen.
Eutrophication of freshwater ecosystems results
in serious water quality problems that can have
broader implications. These include unsightly
algae blooms; depletion of dissolved oxygen,
resulting in fish kills; depreciation of lakeshore
property values; and negative impacts to
recreational uses in and around the lake.
As shown in the Figures 1 and 2, all lakes and
ponds will eventually yield to eutrophication,
but human activity can accelerate this process
significantly-unduly shortening the life of
a lake or pond if left unchecked.
If we want to slow down the eutrophication process, we
need to modify our cultural behaviors. One of the primary
ways we can effect change is to limit the phosphorus inputs
to our water bodies. Sources of phosphorus include
fertilizers, sediment, automobile exhaust, wash water, and
human and animal waste. Phosphorus is conveyed to
Crystal Lake via stormwater runoff. Although it is
unrealistic to think stormwater runoff ever will be
completely “clean” in our modern society, the quality
certainly can be improved. There are many things that you
can do to improve stormwater runoff quality and to reduce
the ecological impacts to Crystal Lake:
- Test your lawn to determine what nutrients it needs
before applying fertilizer, and consider using lawn
clippings and compost as part of your lawn-care regimen.
- Switch to zero-phosphorus fertilizer. Those with
phosphorus are unnecessary (unless starting a new lawn)
because phosphorus is abundant in our local soils— and it costs less to make the switch!
- Utilize the City’s free yard-waste collection, and never
dispose of grass clippings along the bank of any lake,
stream or river.
- Reduce and/or treat stormwater runoff from your own
property as much as possible. Consider planting a rain
garden, using rain barrels or dry wells and replacing
impervious areas, such as driveways and patios, with
permeable pavers or porous pavement.
- Use a car wash, where water is treated and recycled,
instead of washing your car in your driveway, where
detergent-laden water may enter the drainage system.
- Pick up after your dog, and properly dispose of the waste
in the garbage.
- Reduce areas of exposed soil on your property to
eliminate sediment runoff in the drainage system.
Perform regular maintenance on your septic system to
- Do not feed wild animals, especially geese and ducks, to
minimize animal waste in the lake.
The City supports these initiatives with various educational
programs and strives to set a positive example. Recently, the
Department of Public Works installed a water quality treatment
device and a series of underground recharge units to infiltrate
the stormwater runoff from the Crystal Lake bathhouse
parking lot—which previously discharged directly to the lake,
and the Parks and Recreation Department specified zero-phosphorus
fertilizer for maintenance of 200 acres of land.
Crystal Lake Water Quality Report