|
What
is a TMDL and what does it mean for the river, the watershed,
and area residents?
The
letters in TMDL stand for Total Maximum
Daily Load. EPA defines a TMDL as "a calculation
of the maximum amount of a single pollutant - from all
contributing point and nonpoint sources - that a waterbody
can receive and still meet water quality standards [without
adverse impact to fish, wildlife, recreation, or other
public uses]...." That calculation must include a margin
of safety and account for seasonal variations in water
quality.
The
Clean Water Act of 1972, section 303, established the
water quality standards and TMDL programs. The Act,
which has had subsequent revisions, also required the
states to identify the waters not meeting the standards
[303(d) list], to set priorities for TMDL development,
to develop a TMDL for each pollutant for each listed
waterbody, to detail a Water Quality Management Plan
with quantitative goals for implementing the load allocations
and for reducing the pollutants using a variety of regulatory
and nonregulatory approaches, and to provide the public
with the opportunity to comment on the plan.
The
State of Connecticut identified the Norwalk River as
a Class B river, i.e., fishable and swimmable,
and stocks the river as part of its recreational programs.
The Norwalk could not be classified as a Class A river
(drinking water potential), even though the Kellogg/
Deering wellfields off the river help supply Norwalk
First Taxing District's water supplies, because the
river is impaired.
The
1996 Streamwalk had identified 132 impaired sites, and
DEP listed the Norwalk River as failing to meet its
designated uses for 1) contact recreation (because of
fecal coliform bacteria), 2) aquatic life support (perhaps
from high temperatures or toxic ammonia levels), and
3) migratory fish passage (because of dams). A more
complete list of cited impairments that degrade water
quality include bacteria, high water temperature, decreased
dissolved oxygen, increased algal growth, restricted
flows, extra high and low flows, loss of riparian habitat,
altered streambanks, channelization in developed areas,
historic industrial spills, contaminated sediments,
hydrocarbons, metals, and dams.
Pollution
comes from both point and nonpoint sources. Point sources
would include malfunctioning sewage treatment plants
and other distinct sources. [The river accepts treated
effluent from four sewage treatment plants: upstream
at two in Ridgefield and one in Georgetown, and one
at the harbor in Norwalk.] Nonpoint sources typically
come from malfunctioning septic systems, urban runoff,
and both permitted stormwater discharge and runoff from
fertilizers, herbicides, pesticides, and manure from
wildlife (waterfowl, horses, and pets). Indentification
of problem areas and education of the public to improve
them will make a difference to nonpoint pollution.
Besides
education, how is NRWA trying to help improve the water
quality? Early in 2001, NRWA and representatives from
Harbor Watch/River Watch and the NRW Initiative went
to Hartford and met with representatives from DEP and
EPA to request that TMDLs be imposed on the entire river
to encourage all factions to improve water quality.
Years of testing by Harbor Watch/RiverWatch had documented
little improvement. Clearly new incentives were needed
to force action. Four months later DEP did impose TMDLs
on the entire river and in March 2002 identified the
testing sites to benchmark problem areas and improvements.
Meanwhile,
NRWA is working to have Ridgefield extend by two months
the operation time of its ultraviolet lights, which
dramatically reduce coliform counts at the two Ridgefield
plants, to encompass April through October, the most
likely times for river contact through swimming and
fishing (although fishing season continues through February).
The Town of Redding has historically voluntarily engaged
its UV lights all year long*.
NRWA
is also funding additional water tests by Harbor Watch/River
Watch at other polluted areas to pinpoint problem sources
and to quantify ammonia and nitrogen/phosphorous levels
that seriously threaten aquatic life. This information
is useful for establishing TMDLs and upgrading sewer
permits.
TMDLs
are a great incentive to identify pollution sources
and the improvements needed to effect better water quality.
Under a TMDL additional technical help becomes available,
as well as certain loans and grants. Those Mayors or
First Selectmen who sign onto the program for their
towns - all of which have in the past supported the
Norwalk River Watershed Action Plan and its important
goals - can expect government support for the improvements
they would like to make for the safety of their constituents
now and in the future.
*Note:
The Town of Redding would put on its lights if it could,
but it has been having problem with its UV lights, so
they aren't working properly.
For
additional information check: http://www.epa.gov/owow/tmdl/states/ctfact.html
; Clean Water Network: www.cwn.org:
Status
Reports March 2000 The Clean Water Act: An Owner's Manual,
pp. 81-89; The River Network: www.rivernetwork.org
|