Section 319
NONPOINT SOURCE PROGRAM SUCCESS STORY
Implementing Best Management Practices on Pasture Reduced Bacteria
Levels in Little Silver Creek
A/ t h H I H Bacteria loadings from pasture and livestock led to high bacteria
VaterDOay I improved counts in Louisiana's Little Silver Creek that violated water quality
standards. As a result, the Louisiana Department of Environmental Quality (LDEQ) added Little Silver
Creek to its 2008 Clean Water Act (CWA) section 303(d) list of impaired waters for failing to attain its
primary and secondary contact recreation uses due to fecal coliform bacteria. Agricultural producers
used pasture renovators, AerWays and grain drills to increase water infiltration and decrease the
amount of fecal coliform runoff to the creek. As a result, fecal coliform levels decreased and Louisiana
removed the fecal coliform impairment for Little Silver Creek from its 2014 list of impaired waters.
Problem
The 13-mile-long Little Silver Creek is a tributary to
the Bogue Chitto River, which is in the Pearl River
Basin in eastern Louisiana, close to the Mississippi
border. The Pearl River Basin is bordered on the
west and south by the Lake Pontchartrain Basin.
Land use in the Little Silver Creek watershed is
primarily pasture land, forest land and crop land
(Figure 1). The watershed supports approximately
three dairy farms and 30 beef and horse producers
(with around 2,700 head of livestock spread across
10,832 acres).
Bacteria loadings from pasture land and livestock
led to high bacteria counts in Louisiana's Little
Silver Creek. Louisiana's water quality standards
for primary contact recreation require that no more
than 25 percent of the fecal coliform samples col-
lected on a monthly or near-monthly basis from May
to October may exceed a fecal coliform density of
400 colonies per 100 milliliters of water (col/100 ml).
For secondary contact recreation, no more than
25 percent of the fecal coliform samples collected on
a monthly or near-monthly basis may exceed a fecal
coliform density of 2,000 col/100 mL year-round.
Monthly water quality sampling in 2006 (Figure 2)
indicated that the fecal coliform standard was not
being met due to an exceedance rate of 60 percent
and 36 percent for primary and secondary contact
recreation standards, respectively. As a result, LDEQ
added Little Silver Creek to Louisiana's 2008 CWA
section 303(d) list of impaired waters for failing to
attain its primary/secondary recreation designated
use due to high levels of fecal coliform bacteria.
Legend Land Use
Pasture or hay
^H Evergreen forest
Deciduous forest
Urban or built up land
Forested wetland
Soybeans
Com
•• Water
Grave! pit or strip mine
Transitional area
Figure 1 . The Little Silver Creek watershed is in eastern Louisiana.
A total maximum daily load (TMDL) was completed
for fecal coliform bacteria in August 2010. To meet
the state's water quality standards, the TMDL indi-
cated that fecal coliform bacteria must be reduced
by 68 percent during the winter months and 98 per-
cent during the summer months.
Project Highlights
The Capital Resource Conservation and
Development (RC&D) Council used CWA section 319
funds to purchase grain drills, pasture renovators
and AerWay equipment, which were then provided
to landowners through a low-cost rental program.
-------
Use of the equipment improves soil conditions
and reduces polluted runoff. In 2009, landown-
ers used grain drills on 2,248 acres, allowing for
direct seeding of pasture sod without tilling the
landscape. According to an analysis using the U.S.
Department of Agriculture's Revised Universal
Soil Loss Equation (RUSLE), using this equipment
lowered the estimated annual sediment loss from
10 tons per acre per year to 1 ton per acre per year.
In addition, because less fertilizer is needed on
land prepared with grain drills, less polluted runoff
leaves the pasture areas.
From 2010 to 2011, landowners used pasture reno-
vators on 275 acres. Pasture renovators use blades
to slice through dense pasture sod and fracture
the pasture soil, allowing water to penetrate to
the plant root zone. This process reduces runoff
by allowing for better plant growth in the pasture
and decreased erosion. Farmers noted healthier
grasslands when this practice was applied.
In 2011, 42 producers used AerWay aerators on
2,003 acres. AerWay equipment has metal tines
that break and lift the soil, allowing direct broadcast
of pasture sod seeds without tilling. According to
the RUSLE analysis, the use of AerWay equipment
reduced soil erosion by 15,623 tons per acre per
year in the Little Silver Creek watershed. Other best
management practices (BMPs) implemented in the
watershed included conservation cover, prescribed
grazing, waste recycling and nutrient management.
Results
The rapid improvement in water quality following
BMP implementation indicates that the major source
of bacteria impairment was addressed by restora-
tion efforts. Monthly bacteria data from 2012 and
2013 (see Figure 2) indicated that in May-October,
zero of six values exceeded 400 col/100 mL (0 per-
cent exceedance rate); year-round, one of 12 values
exceeded 2,000 col/100 mL (8 percent exceedance
rate). These data show that fecal coliform bacteria
concentrations are below the 25 percent exceed-
ance rate maximum identified in the applicable
water quality standards. As a result, LDEQ removed
the fecal coliform impairment for Little Silver Creek
from its 2014 list of impaired waters. The farmers
continue to use the equipment on the pasture lands
to maintain these improvements.
Fecal Coliform in Little Silver Creek
16000 16000
/x/y
Figure 2. Monthly fecal coliform data collected in Little Silver
Creek show violations of the water quality standard in 2006.
Three of five values collected during May-October 2006
exceeded 400 col/100 mL (a 60 percent exceedance rate) and
four of eleven values collected year-round in 2006 exceeded
2,000 col/100 mL (a 36 percent exceedance rate). By 2012/2013,
data showed that the creek met water quality standards.
Partners and Funding
Numerous federal, state and local partners contrib-
uted to the water quality improvement in the Little
Silver Creek watershed. The pasture renovator proj-
ect received $9,500 in CWA section 319 funds with
an in-kind match of $22,911 provided by the Capital
RC&D Council and participating landowners. The
grain drill project received $74,000 in CWA section
319 funds with a match of $94,164 provided by the
local soil and water conservation districts (includ-
ing the East Baton Rouge, East Feliciana, West
Feliciana, St. Helena, Tangipahoa and Bogue Chitto
soil and water conservation districts); the Louisiana
Cattlemen's Association; and the Kentwood, Spring
Creek and Tri-Parish farmers' co-ops. The AerWay
project received $34,500 in CWA section 319 funds
with an in-kind match of $116,889 provided by
partnering producers and the Kentwood and Spring
Creek co-ops.
Additional funding sources used to support
watershed improvement projects within the Silver
Creek watershed include the U.S. Department of
Agriculture's Environmental Quality Incentives
Program, Wildlife Habitat Incentives Program,
Conservation Reserve Program and Conservation
Technical Assistance Program.
UJ
(9
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-14-001WW
September 2014
For additional information contact:
Karen Vidrine, Senior Scientist
Louisiana Department of Environmental Quality
225-219-1208
Karen.vidrine@la.gov
------- |