Water Quality Monitoring Programs in Fairfax County, April 2014
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2. Monitoring Milestones
1969 - Health Department stream monitoring
1984 - Gunston Cove ecological study
1986 - Kingstowne environmental monitoring program
1998 - Stream Protection Strategy
2002 - Perennial streams mapping project
2002 - Stream Physical Assessment
2003 - Watershed management plan development
2007 - UGSG gages partnership/study
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3. Early Surface Water
Monitoring
…any open, unprotected body of water is subject to pollution from indiscriminate dumping of
litter and waste products, sewer line breaks and contamination from runoff
pesticides, herbicides, and waste from domestic and wildlife animals. Therefore, the use of
streams for contact recreational purposes, such as swimming, wading, etc., which could cause
ingestion of stream water or possible contamination of an open wound by stream
Fairfax County Health Department
Annual Stream Water Quality Report
• Initiated in 1969
• Bacteria (fecal coliforms), temperature, pH,
nitrogen, phosphorus, dissolved O2 and
heavy metals
• 85 sites – sampled 2x monthly
• Ceased in 2003 – program assumed by
Stormwater Planning (DPWES)
• Annual statement:
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4. Early Surface Water Quality Monitoring
Gunston Cove
Ecological Study
Ongoing 30-year study (est. 1984)
Partnership with GMU
Observe effects of wastewater
treatment plant (WWTP) on
estuary
Very poor ecology 1970s-80s
(eutrophication)
Evaluate
WQ parameters
Phyto-, zoo- and ichthyoplankton
Adult and juvenile fish
Submerged aquatic vegetation
Bentic macroinvertebrates
Internationally recognized case of
ecosystem recovery
TIME LAGS (10 to 15 years)
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5. Early Surface Water Quality Monitoring
Kingstowne Environmental
Monitoring Program
23-year study (1986-2012)
Large scale development project
upstream (1.8 mi2)
Huntley Meadows Park wetlands
downstream (1,500 ac)
Potential siltation of wetlands
Measure storm and baseflows
Evaluate watershed-wide BMP
efficiencies
Average total suspended solids
(TSS) efficiency greater than 80%
Trend analysis: downtrend in TSS
(1986-2001)
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6. Stream Biological Monitoring Program
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Fairfax County Stream Protection
Strategy (SPS)
Established by BOS in 1998 to assess
WQ/stream/watershed conditions Countywide
Evaluated chemical, biological, habitat and
geomorphic conditions at 124 sites in 1999
2001 SPS Baseline Study
>70% of streams in fair to very poor condition
(impaired)
Urbanization, imperviousness and STW
implicated as primary stressors
Established management categories (3)
Recommendations included: SPA, develop
WMPs, long-term monitoring program, explore
STW Utility. All implemented!!
8. Stratified-random evaluation framework (2004)
Similar to VA’s probabilistic monitoring
program
Sites stratified by stream order (1st – 5th)
Statistically valid way to make inferences on
countywide stream condition
40 sites selected annually. Sampled for:
Benthic Macroinvertebrates (spring)
Fish and habitat (summer)
Bacteria (quarterly)
Water quality (every visit)
12 reference sites
Annual Stream Quality Index (SQI) [score 1-5]
Stream Biological
Monitoring Program
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9. Dry Weather Screening
Screening program for illicit discharges or
improper connections to storm drainage network
100 - 120 outfalls screened annually
Suite of chemical and physical parameters tested
Parameter exceedance triggers recheck and/or
trackdown of upstream source(s)
Investigations fully documented
Highly effective at detecting and eliminating
pollutants from surface waters
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10. Wet Weather Screening
Storm event monitoring program
High-intensity land use areas
Target areas with high pollution
potential
Prioritized site selection protocol
Two sites monitored each year
Sampled quarterly (8 events)
Stormwater tested for full suite of
conventional runoff pollutants
Exceedences may trigger trackdowns
or referral to Industrial and High
Risk Runoff (IHRR) inspection
program
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11. Watershed Monitoring
Ongoing since 2003
Paired watershed study
Storm runoff sampled
Evaluate trends in WQ
Characterize runoff from
different land uses
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12. Special Studies
2002-2004 USGS Partnership:
Accotink Creek Bacteria (TMDL)
Source Tracking Study
Large suite of biological and
chemical tracers used
more than 100 sites sampled (in one
day) every quarter
“Hot spots” identified
Bacteria ubiquitous throughout
densely-populated upper watershed
Improved sampling techniques
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13. Innovative Stormwater BMP Monitoring
Monitored 2008-2012
3 sites - county stormwater retrofits
2 rain gardens, 2 green roofs
Data analysis by VA Tech Occoquan
Watershed Monitoring Laboratory
(OWML)
Excellent pollutant and volume
reductions on smaller storms (greater
than 2”)
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14. Innovative Stormwater
BMP Monitoring
Cinnamon Oaks dry pond retrofit
Monitored 2010 to present
Partnership with VA Tech OWML
Calculate pollutant loads (in vs. out)
Calculate removal efficiencies
Improve future retrofit
designs, construction and
maintenance
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15. Lake Studies
Lakes Huntsman and Barton
Highly eutrophic (nutrient rich)
Dredging schedule
Characterize lake…
Water quality issues (no O2 greater
than 4’ deep)
Employ circulation
Continue monitoring
Post-dredge lake restoration
Goal: maximize ability of these
lakes to provide water quality
improvements to downstream
waters
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16. USGS Partnership: Stream Gaging Study
Initiated in 2007 in conjunction with the USGS VA Water
Science Center (Richmond)
Billion$ being spent nationwide on Stormwater BMPs
How well is our current technology working?
Many studies on site-specific BMP performance, but...
…what about watershed-level responses?
Paramount study at small watershed scale to quantify sediment
and nutrient yields and effects of BMP implementation
Benefits from study/data?
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17. Stream Gage Study with USGS
Objectives:
1. Generate long-term monitoring data to describe:
Current water-quality conditions
Trends in water-quality, nutrient and sediment
loads and yields
2. Evaluate relations between observed
conditions/trends and BMP implementation.
3. Transfer the understanding gained to other less-
intensively monitored watersheds.
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18. Gage Study: Objective #1
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Operate 4 intensive monitoring
stations
10+ years of data collection
Continuous-record stream gage
Continuous water-quality monitor
Turbidity, pH, SC, temp, DO
Nutrients and Sediment Sampling
Automated sampler (storm samples)
Scheduled monthly sampling
Annual benthic macroinvertebrate
monitoring
1. Generate long-term monitoring data to describe:
Current water-quality conditions
Trends in water-quality, nutrient and sediment
loads and yields
19. Gage Study: Objective #2
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2. Evaluate relations between observed
conditions/trends and BMP implementation
20. Gage Study: Objective #3
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Operate 10 less-intensive
monitoring stations
Partial-record stream gage
Nutrient and sediment sampling
Scheduled monthly sampling
Annual benthic macroinvertebrate
monitoring
Evaluate relations between trend - and
intensive monitoring sites
Saves $$$ while expanding dataset
and predictive capabilities
3. Transfer the understanding gained to other less-
intensively monitored watersheds
21. Gage Study:
Monitoring Network
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• Site selection optimized using
statistical analyses of large dataset:
• land use
• impervious cover
• physical stream condition
• biological scores
• planned BMP implementation
• 14 sites:
• 4 fully-gaged sites (continuous
data collection)
• 10 partial-record sites (scheduled
data collection)
• All watersheds greater than 5 mi2
• Expanded in 2011 (6 sites added)
• 1 fully-gaged site
• 5 partial-record sites
22. Gage Study: Data Analyses and
Benefits
Rich dataset allows for enormous amount of robust analyses
Characterize baseline conditions after 5 years
Trend analysis after 10+ years
Ultimately show effect of BMPs on watersheds
Unanticipated learning (Triassic basin P)
Data inform restoration designs
Publication imminent (1st five yrs. data)
Several “piggyback” studies describing:
Floodplain dynamics
Sediment transport
Stream metabolism
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23. Gage Study: Data Analyses & Benefits
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Compare to other systems
Atlanta urban streams
North Carolina study
Occoquan watershed
USGS bay-wide network
Chesapeake Bay Model “Reality
Check”
Compare monitored data to modeled
data
Potentially use to calibrate
Evaluate load allocations
Unique dataset (smaller watersheds)
24. Gage Study: Data Access
All data published on WWW
for viewing and downloading
Near-real time (updated hourly)
Stream flow (5 min. intervals)
Stream discharge (5 min. intervals)
WQ parameters (15 min. intervals)
As received (from laboratories)
Sediment (TSS)
Nutrients (N and P species)
Available for viewing and
downloading in both tabular
and graphical formats
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25. So… what do we know??
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Monitoring is necessary, but not cheap.
Stream conditions have changed little …so far.
26. So… what do we know??
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Time lags are REAL – results don’t manifest overnight.
Cleaning up Stormwater runoff is technically challenging
and expensive – but we’re definitely getting better!
Floodplains, wetlands and other preserved natural areas are
providing beneficial functions
Urban streams may never recover full functionality…
Likely need to target for “best attainable conditions”
No “silver bullet” cure. Will require multi-faceted approach
Government(s) can not do it alone
27. Thank you.
Shannon Curtis, Ecologist IV
Stormwater Planning Division
Department of Public Works and Environmental
Services
Fairfax County
703-324-5500, TTY 711
www.fairfaxcounty.gov/dpwes/stormwater
A Fairfax County Publication, April 2014
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Notas del editor
First stream WQ monitoring program started by HDSPS at the core of our monitoring programsPerennial Streams – developed evaluation protocol and applied to all headwater streamsresulted in countywide map and expanded protection of riparian buffers for water quality benefitsPerennial Streams - added 330 miles (63% increase)RPAs – 17 square miles new bufferSPA– evaluated 850 miles of stream countywideWMPs – 7 years developing plans. Identified 1,700 projects at cost of $800M – lot of work to do!USGS gages – will be large focus of this presentation
Move on to our CORE monitoring programs that are ONGOING.Stream program is at the HEART of our monitoring programs
Move on to our CORE monitoring programs that are ONGOING.Stream program is at the HEART of our monitoring programs