Testimony Feb 3, 2010
To:
Salmon City Council
From:
Calvin B Leman, PhD
208-756-4104
305 Washington Street, Salmon, Idaho
http://votingpeoplehelpingpeople.com/
Date:
February 3, 2010
Subject:
Finding the best
wastewater solution for the people of Salmon.
At our workshop on
January 25, you told me that you thought the wetland and agriculture
solution, which I described for effluent from the lagoon, was a good
idea. The main problem
that we discussed was getting the land. Since last week, we
have discovered that we are fortunate enough to have the ideal
parcel available now. Mike Overacker's Ranch (208-756-2809), which
is just across the street from the lagoon, is available now and Mike
has use for the water now: the sprinklers are in place.
Because this is the decision-making time for this solution, it would
be the ideal time to make the right decision.
This land may not be available in the future.
Other towns have built constructed wetlands for ½ to 1/8 the
cost, according EPA and Army Corps of Engineers publications.
To make the right
decision, we need help from an engineering firm, who understands
wetland solutions, who has built wetland solutions, and who
can evaluate our specific situation, now that we have a location for
the constructed wetland.
This morning I talked with
Jim Phillips (Rural Development Specialist-Environmental for RCAC
208/841-9714I) about helping with this
project. I have talked
with Ron Crites (Brown & Caldwell 530-204-5204), Paul McGuire
(Morrison & Maierle 406-542-4819), and will be talking with Larry
Brown, from Ohio State University.
These engineering firms and university have experience with
constructed wetland solutions.
Larry Brown was a part of the
Wetland
Reservoir Sub-irrigation System[i], which I
am giving you as reference today.
Ron Crites wrote the document[ii] that I
told you about at the workshop.
All of this information is on the website.[iii]
Arm-chair
engineering and theoretical calculations, as we have been doing,
cannot distinguish if a wetland is a common-sense way to use the
wastewater from Salmon.
We really have to look at the land.
For example, from October to March, the effluent is about
1mgd, which requires 50 acres, if 10 feet deep.
That is about as far as we can get, without help from an
engineer, who understands wetlands and can evaluate our specific
situation. We also need
help evaluating if infiltration has any effect at all on a wetland
solution. Two reservoirs
connected by a free water surface or subsurface wetland may be a
common-sense solution.
A wetland solution
may not require fixing the infiltration, because other towns use
wetlands for far more water than Salmon will ever generate.
What data or what guarantee do we have to show that fixing
the infiltration will stop EPA violation notices, like Salmon
received on October 8, 2008, for 120 violations?
The Natural
Resources Conservation Service (NRCS) may match city funds to build
a wetland. Idaho
Department of Environmental Quality (DEQ) may match city funds to
evaluate this constructed wetland solution for Salmon wastewater.
We may be able to match the NRCS grant with the DEQ grant.
The people of Salmon
elected you to research and to find the best solutions possible.
This is a big responsibility. Now is your opportunity to take
care of this wastewater situation with a solution, which will
benefit the people of Salmon now and in the years to come.
|
[i]
A Wetland Reservoir
Sub-irrigation System (WRSIS)
is an innovative agricultural water management
system. WRSIS is a wetland and a water storage
reservoir linked to a network of subsurface pipes to
either drain or irrigate crops.
Runoff and subsurface drainage are collected
from cropland into a constructed wetland. Natural
processes in the wetland remove some of the
nutrients, pesticides, and sediment. The water then
goes to a storage reservoir and held until needed to
irrigate crops.
The storage reservoir also provides a further
cleaning of the water.
The integration of these components allows
WRSIS to operate in a closed loop mode most of the
time.
WRSIS can offer a number of benefits including (1)
enhanced crop yields, (2) reduced offsite release of
nutrients, pesticides, and sediment, (3) additional
wetland vegetation and wildlife habitat, (4) more
carbon sequestration in soil, and possibly, (5)
decreased flooding potential downstream.
http://www.ars.usda.gov/Research/docs.htm?docid=14999 |
[ii]
Abstract
Constructed wetlands have
considerable potential for use in upgrading treatment pond
systems. In 1998 the pond system used by the City of Cle
Elum had a history of violating its NPDES permit.
Flows and loadings to its treatment plant were
projected to grow significantly in the next twenty years,
yet the treatment plant was already at capacity.
Planning efforts were conducted to evaluate the
relative merits of several alternative long-range plans to
accommodate increased wastewater flows and loads due to
population growth in the area. Conversion of the third
lagoon to a constructed wetland was chosen as an interim
upgrade to handle increased treatment capacity and more
stringent discharge requirements.
The new revised permit
required BOD and TSS concentrations not to exceed 30 mg/L
and a minimum removal of 85 percent of the incoming BOD and
TSS loads. The
treatment efficiency was the driving design parameter
because of high infiltration/inflow (I/I) from the spring
snow melt that creates a dilute waste stream requiring
effluent BOD concentrations of 14 mg/L. Actual performance
for BOD and TSS removal has ranged from 94 to 98 percent.
The wetland consists of a
series of three planted zones separated by two open zones.
The planted zones, totaling 68 percent of the total
area, are 1.5 feet deep and are planted with hardstem
bulrush, Scripus
acutus, a common native wetland plant.
The open zones are 3 feet deep, which prevents growth
of wetland plants.
The planted zones allow for denitrification and BOD
removal. The
open zones reduce short-circuiting and allow natural
aeration to increase dissolved oxygen.
[iii] http://votingpeoplehelpingpeople.com/
