Post on 16-Mar-2016
description
Interpreting and Using Existing Data to Identify
Pollution Causes and Sources
Confirm impairments and identify pollutants
Compare available monitoring data to wqs:• Document magnitude of impairment• Document seasonal/temporal patterns• Document spatial distribution
Spatial Analysis
• Isolate critical subwatersheds• Combine with land use/land cover data
Flow Relationships
• Point vs. Nonpoint
Flow Relationships
• Point vs. Nonpoint
Temporal Analysis
• Seasonality• Stratify data by potential source activities
– Tillage– Crop canopy development– Manure/fertilizer applications– Grazing season– Logging– Construction projects– Street cleaning
Other tools:
• Stakeholder knowledge• Direct observation (streamwalk)• Specialized tools, e.g., microbial source
tracking, ground water aging
Supplementing available data
– Windshield surveys– Interviews with residents– Volunteer monitoring– Bioassessment– Targeted sampling– Chemical/biological sampling
Helps lay the groundwork for implementation!
Examples
St. Albans Bay VT RCWP
• Known WQ impairment due to eutrophication– Obvious algae blooms & macrophyte growth– Declining State Park visits, beach closures– State DEC P monitoring
• Excessive P loads to Bay• 75% point source/25% nps
• NRCS knowledge about current status of animal waste management, milkhouse waste, cropland erosion
St. Albans Bay VT RCWP
Lake Pittsfield IL• Lake Pittsfield is a 220 ac
lake located near the city of Pittsfield in the 25,393 ac Blue Creek watershed in Pike County, western Illinois
• Constructed in 1961 as a flood control reservoir.
• Sediment deposition the dominant water quality problem
0
500
1000
1500
2000
2500
3000
3500
4000
1961 1974 1979 1985 1992
Lake
Vol
ume
(ac-
ft)
01002003004005006007008009001000
Sedi
men
t Vol
ume
(ac-
ft)
Lake volume Sediment volume
Lake Pittsfield IL
• 1979 vegetative practices on agricultural land slowed sedimentation rate
• Lake sedimentation still higher than desired• Additional practices needed – WASCOBs and
sediment retention basins
Lake Pittsfield IL
Ann
ual S
edim
ent Y
ield
(ton
s/ac
re) o
r
Y
ield
/Dis
char
ge (t
ons/
ac-f
t)
0
2
4
6
8
10
12
WASCOBs installedConstruction of 12 rock riffles (Newbury Weirs)Station D annual sediment yield (tons/acre)Station C annual sediment yield (tons/acre)Station D yield/discharge (tons/ac-ft)Station C yield/discharge (tons/ac-ft)
1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
VT 319 NMP
04-Jan-9512-Apr-95
19-Jul-9530-Oct-95
07-Feb-9615-May-96
19-Aug-9616-Dec-96
31-Mar-9702-Jul-97
06-Oct-9721-Jan-98
29-Apr-9829-Jul-98
09-Nov-98
1
10
100
1000
10000
100000
1000000
E C
oli C
ount
s (#
/100
ml)
WS 1
WS 2
WS 3
E. Coli Counts 1995 - 1998Lake Champlain Basin Ag Watersheds NMP Project
VT 319 NMP
0.1 1 10 100 1000
Instantaneous Streamflow (ft3/sec)
1
10
100
1000
10000
100000
1000000
E. C
oli C
ount
s (#/
100
ml)
Streamflow and E. Coli CountsWS 2 1995 - 1998
Lake Champlain Ag Watersheds NMP Project
VT 319 NMP
0.1 1 10 100 1000
Instantaneous Streamflow (ft3/sec)
1
10
100
1000
10000
100000
1000000
E. C
oli C
ount
s (#/
100
ml)
WinterSummer
Seasonal Streamflow and E. Coli CountsWS 2 1995 - 1998
Lake Champlain Basin Ag Watersheds NMP Project
VT 319 NMP
VT 319 NMP
Identification of stressors
• Where causes of biological impairment are unknown, use characterization data to help identify stressors
Stressor Identification
Stressor Identification
Resources:• USEPA Stressor Identification Guidance Document
www.epa.gov/waterscience/biocriteria/stressors/stressors.html
• USEPA Causal Analysis/Diagnosis Decision Information System (CADDIS) http://cfpub.epa.gov/caddis/home.cfm