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Section 319
NONPOINT SOURCE PROGRAM SOCCESS STORY
Ski Resort Improves Stormwater Management and Restores North
Branch Ball Mountain Brook Tributary
Waterbody Improved
Sediment in stormwater runoff from roads, parking lots and roadside
ditches degraded biological communities in Vermont's North Branch
Ball Mountain Brook Tributary #1. As a result, the Vermont Department of Environmental Conservation
(VTDEC) placed the tributary on its 1998 Clean Water Act (CWA) section 303(d) list of impaired waters
for aquatic life use impairments caused by polluted stormwater runoff. Biomonitoring data in 2010 and
2012 showed that Tributary #1 complied with Vermont's aquatic life water quality standard, prompting
the state to remove the segment from the impaired waters list in 2014.
Problem
North Branch Ball Mountain Brook Tributary #1 is in
a heavily developed watershed of 0.9 square miles
in the upper reaches of the West River Basin. This
area includes a wide range of land uses and lies
almost entirely within the holdings of The Stratton
Corporation (Stratton). Stratton owns the Stratton
Mountain Ski Resort and associated adjacent
properties. VTDEC classified the stream as a Class B
water — a designation defined as "suitable for bath-
ing and recreation, irrigation and agricultural uses;
aquatic biota sustained by high quality habitat; good
aesthetic value; acceptable for public water supply
with filtration and disinfection."
Over the years, VTDEC has assessed the biological
integrity of Tributary #1 using several biomonitoring
metrics, including the EPT index (short for the macro-
invertebrate order names Ephemoroptera, Plecoptera
and Trichoptera). The index is a measure of the
number and types of pollution-sensitive aquatic
insects inhabiting a waterbody. Streams with a high
EPT value contain a greater richness (diversity) of
pollution-sensitive aquatic insects, indicating higher
water quality. VTDEC also assessed macroinverte-
brate densities (total number of organisms present),
the percentage of macroinvertebrates consisting
of pollution-tolerant worms of the taxonomic class
Oligochaeta, and the Pinkham-Pearson Coefficient
of Similarity-Functional Group (PPCS-F) metric (a
measure of functional feeding group similarity to a
model, based on the reference streams).
Biological monitoring in the early 1990s found that
Tributary #1 did not comply with Vermont's Class B
water quality standards for aquatic life. The stream
Figure 1. Before restoration, urban runoff contributed to
stream habitat impairment in Vermont's North Branch Ball
Mountain Brook Tributary #1. The right bank visible in this
2007 photograph was one of the areas observed to be
directly contributing sediment to Tributary #1 through erosion
processes.
had low EPT values, macroinvertebrate density
and low EPT/richness. This impaired biological
condition was caused by excessive sediment from
urban runoff degrading stream habitat (Figure 1).
Habitat evaluation revealed a high substrate embed-
dedness. As a result, VTDEC placed Tributary #1
(0.5 miles long, segment VT11-15.01) on its CWA
section 303(d) list of impaired waters in 1998 for
sediment impairment. In 2002 VTDEC completed a
sediment total maximum daily load that outlined the
load reductions necessary to attain water quality
standards in the impaired segment.
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Project Highlights
Stratton developed a comprehensive water qual-
ity remediation plan (the Stratton Water Quality
Remediation Plan, orSWQRP) in 1999 to comply with
Vermont's land development law (Act 250), which
regulates expansions and new developments involving
more than 10 acres, in order to mitigate water quality
problems arising from additional development. The
development of the plan was a collaborative effort
involving the Vermont Agency of Natural Resources
(VTANR), the Vermont Natural Resource Council
(VNRC) and the Stratton Area Citizens Committee
(SACC). Riparian restoration projects implemented
as part of the plan included stream corridor enhance-
ments on the golf course, the creation of no-mow
zones, and additional stream buffer plantings.
Stormwater treatment projects included infrastructure
upgrades to the parking lots and catch basins, culvert
replacements and better placement of plowed snow
during the winter months in the Stratton Village area.
Other smaller-scale projects such as ditch re-grading
were also implemented. On-mountain Stormwater
improvement projects included water bar installations
and repairs, sediment basin installations, and seeding
and revegetation of previously exposed bare earth.
meets the Class B guidelines for EPT index score (>16),
macroinvertebrate density (>300 individuals), percent
oligachaetes (<12 percent), and PPCS-F (>0.4) (Table 1).
In addition, stream embeddedness, which measures
the extent to which fine sediment fills the gaps
around rocks and cobbles in the streambed, has
declined. Before the restoration efforts, the per-
cent embeddedness was measured to range from
50 percent to 75 percent, and a target goal of less
than 25 percent was developed. After restoration,
embeddedness decreased to between 5 percent
and 25 percent. These data indicate that remedia-
tion practices reduced sediment delivery, improved
stream habitat and allowed the stream to meet the
state's standards. As a result, VTDEC removed the
segment from the impaired waters list in 2014.
Partners and Funding
Results
As a result of restoration work in the watershed,
the aquatic habitat of Tributary #1 has improved.
Biomonitoring conducted in 2010 and 2012 showed
that the macroinvertebrate densities and EPT indices
increased, while the percentage of oligochaetes had
decreased. All recent data indicate that Tributary #1
Partners included The Stratton Corporation, VTDEC,
VTANR, VNRC and SACC. VTDEC defined the nature of
the problem in the mid-1990s and assisted in develop-
ment of the SWQRP Stratton was responsible for the
implementation of the SWQRP and remediation of
water quality issues. The bulk of the funding for data
collection and remediation of the problem was funded
by Stratton, in conjunction with redevelopment of
Stratton Mountain. Approximately $20,000 of CWA
section 319 funds were used over the years for water
quality and biological assessments, SWQRP develop-
ment, quality assurance/quality control, and review
of the data collected by Stratton. In addition, VTDEC
expended approximately $20,000 of state funding
toward the project, including many hours of staff time.
Table 1. Biomonitoring Data for Tributary #1 (1990-2012). Values highlighted in red
indicate nonattainment
Monitoring Year
1990
1991
2001
2003
2004
2005
2006
2007
2008
2009
2010
Assessment Rating
-
-
Good-Fair
Good
Very Good
Fair
Fair
Fair
Fair
Good-Fair
Good
EPT Index
15.0
16.0
15.0
18.0
19.0
13.0
17.5
15.0
15.0
16.0
17.0
Macroinvertebrate Density
(Individuals/ Square Meter)
168
102
326
1128
1368
1314
609
476
484
386
420
Percent of Individuals
from Oligochaeta
32.14
3.92
2.15
4.86
0.88
1.73
0.15
0.51
0.51
1.95
1.99
PPCS-F
0.60
0.67
0.38
0.51
0.52
0.38
0.35
0.25
0.40
0.39
0.48
2011 Tropical Storm Irene
2012
Very Good
Class B Guideline
21.0
>16.0
882
>300
0.34
<12.0
0.43
>0.4
UJ
O
U.S. Environmental Protection Agency
Office of Water
Washington, DC
EPA841-F-15-00100
September 2015
For additional information contact:
Tim Clear
Vermont Department of Environmental Conservation
802-490-6135 • tim.clear@vermont.gov
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