Keep the Water Moving
Detention and retention
ponds can be found everywhere, on commercial settings, municipal and residential
areas, on golf courses and construction sites. They serve a variety of purposes,
are cost-efficient, convenient, and for the most part, maintenance free. In
addition, they collect runoff and harmful pollutants such as parking lot
excesses, fertilizers, minerals and sediments, animal waste and other
superfluous nutrients.
Both types
of ponds are used as storm water control devices. They withhold the accumulated
water for a short period of time, allowing minerals and sediment to settle on
the bottom, where plant life begins to consume nutrients. However, once water is
accumulated and unloaded of excesses, detention ponds will pass the additional
water to another waterway while retention/water hazard ponds will rid this water
by transferring it back into the environment via evaporation, seepage into the
ground or through irrigation.
Property
managers, superintendents and facility managers have the responsibility of
maintaining these ponds. Their concern about the relationship between the West
Nile Virus and detention/retention ponds stems from the fact that mosquitoes
thrive and breed in stagnant water and many of these ponds have little or no
circulation.
Since the
outbreak of the West Nile Virus in 1999, the Center for Disease Control
andPrevention (CDC) has
reported more than 4,100 human cases in the United States, including nearly 300
fatalities. The chance of being bitten by a mosquito peaks from late summer to
early fall. Property managers and superintendents are concerned that having a
water feature on their property poses a threat to their patrons, tenants, and
employees.
Reports by the
CDC are both cautionary and assuring, indicating that there is no real reason to
worry, especially when prevention practices are applied.
Charlie Barebo,
CEO of Otterbine Barebo, Inc. explained, "Standing water supports the breeding
grounds of mosquitoes. Therefore, the first step to eliminating the West Nile
Virus is to break the sequence by eliminating the source." The CDC concurs that
the primary role people play in contributing to the continuing cycle of the West
Nile Virus is by maintaining environments, specifically standing water, in which
mosquitoes can lay eggs.
Barebo suggests
installing aerating fountains into all stagnant waterways, and says, "Aerators
and aerating fountains are an effective and efficient solution. They break the
surface of water and create circulation. These effects restrict eggs or larvae
from completing the lifecycle, and also hinder females from laying eggs."
Over the past
three years, the Chicago Park District in Illinois has installed aerators
and fountains to prevent lagoon water from stagnating. For
the past two years, property managers for Musikfest, a 10-day music festival in
Bethlehem, Pennsylvania, have installed aerators in surrounding canals.
Musikfest annually attracts more than one million people from around the
country. "Aerators keep the canal water moving, which keeps the mosquitoes
away," says Musikfest spokeswoman Sharon McCarthy. "The fountains create a
lovely backdrop to our main stage concert venue, and are a wonderful addition to
the ambiance and excitement of an outdoor summer event."
Besides
circulating stagnant water, aerating fountains characteristically offer added
benefits of aesthetics and oxygenation, which is particularly beneficial to
lessening the amount of algae and odors. Because of the tremendous amount of
nutrients constantly entering retention and detention ponds, it is not uncommon
to have excessive algae problems which discolor the water, cause odors, kill
fish and create anoxic conditions. This not only accelerates the aging process
of the pond, but lessens its ability to properly filter water.
Aerating
fountains infuse the water with oxygen, which helps good bacteria break down
excess nutrients, prevents sludge from settling at the bottom and keeps water
clear, clean, and odor free. "The benefits to the property manager of aerating
fountains for water quality are tremendous. They are very cost effective to
operate, and add to the overall beauty of a landscape. This effect can even be
expanded into the night with the addition of lights," Barebo adds.
Source:
Irrigation and Green Magazine, September 2003, www.igin.com
