Catchment Validation Study Final Monitoring Plan February 2012

Catchment Validation Study

Final Monitoring Plan

Prepared for: USDA Forest Service Paci fi c Southwest Research Station

February 2012

2009

500 Seabright Avenue Suite 205 Santa Cruz CA ph 831.426.9119 w 2ndnaturellc.com

SNPLMA Round 11 Catchment Validation Study: Monitoring Plan p.

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CATCHMENT VALIDATION STUDY

RESEARCH INTRODUCTION

Recently a suite of Tahoe Basin urban stormwater management tools has been developed and adopted by the

Lake Clarity Crediting Program (Crediting Program; LRWQCB and NDEP 2009) to support the implementation and tracking of pollutant load reduction actions under the guidance of the Lake Tahoe TMDL. The TMDL analysis has identified that fine sediment particles (<16μm; FSP) are the primary pollutant of concern impacting lake clarity and stormwater runoff originating in urban areas is estimated to contribute 72% of the annual FSP pollutant load to Lake Tahoe (LRWQCB and NDEP 2010). The Crediting Program recommends the use of the

Pollutant Load Reduction Model (PLRM; NHC et al. 2009), Road Rapid Assessment Methodology (Road RAM; 2N et al. 2010c) and Best Management Practice Maintenance Rapid Assessment Methodology (BMP RAM; 2N et al.

2009) by local jurisdictions and regulators to estimate and track urban load reductions over time. The Lake Tahoe

TMDL and Crediting Program are committed to the use of these tools to manage the TMDL Clarity Challenge into the future, yet a number of key questions and potential tool improvements remain. 2NDNATURE, LLC (2N) and Northwest Hydraulic Consultants (NHC) have received funding from the US Army Corps of Engineers (US

ACE) and a SNPLMA Round 11 research grant to validate the tool interactions through a catchment-scale, onthe-ground verification of the tool inputs and outputs.

FUNDING

US ARMY CORPS OF ENGINEERS PILOT STUDY

In 2010, the US Army Corps of Engineers (US ACE) funded The Pilot Catchment Validation Study to test the integration of the urban stormwater management tools on a single urban catchment for WY2011. The primary objective of the Pilot Catchment Validation Study was to develop, test and refine data collection protocols, PLRM modeling techniques, and data analysis approaches to facilitate a catchment scale comparison of pollutant load observations with PLRM predictions. The Osgood Basin catchment was selected, as the site was currently instrumented for additional US ACE/SNPLMA stormwater research making it feasible to instrument and monitor with the resources provided for the pilot scale method development effort. The Pilot Catchment Validation and

Testing of Existing Tahoe Basin Stormwater Tools Data Collection Plan (2N and NHC 2011; ftp://2ndnaturellc.com/2ndnature/2NDNATURE_Reports/Lake%20Tahoe/Pilot%20Catchment%20Monitoring%2

0Plan%20Final.pdf

) was released in April 2011 and detailed the monitoring approach, data collection strategy, and field, sample analysis, and data management protocols. The methods, results and recommendations from the Pilot Catchment Validation Study are included in the Focused Stormwater Quality Monitoring to Inform PLRMv1

Assumptions & Evaluate Predictive Capabilities Technical Report (2N and NHC expected April 2012).

SNPMLA ROUND 11 RESEARCH

A SNPLMA Round 11 research grant was awarded to 2N and NHC in August of 2011 to build upon the US ACEfunded Pilot Catchment Validation Study, resulting in the instrumentation, PLRM modeling and analysis of 3 urban catchments for one complete monitoring year. This Catchment Validation Study Monitoring Plan is an update to the Data Collection Plan (2N and NHC 2011) prepared for the US ACE in April 2011 and provided as

Appendix A. This monitoring plan supplements the information provided in the US ACE plan, updating key sections such as the research schedule, goals and objectives, and site selection, but is not intended as a standalone document. Much of the research approach, data collection, sample analyses, and data management

2 ND NATURE , LLC 500 Seabright Avenue Suite 205 Santa Cruz CA 95062 p 831.426.9119 w 2ndnaturellc.com


protocols remain the same from the US ACE funded research and thus, to maximize resource efficiency, are not repeated here.

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RESEARCH SCHEDULE

Table 1 provides the original schedule for the SNPLMA-funded research. Due to USFS contract delays and inventory backlogs from the equipment supplier the team was incapable of initiating monitoring at the start of water year 2012 (October 1). To ensure monitoring encompasses a complete water year and maintains consistency with the season definitions (Table 2) of the Lake Tahoe Municipal NPDES permit

( http://www.swrcb.ca.gov/lahontan/water_issues/programs/tmdl/lake_tahoe/npdes.shtml

), and because this catchment scale monitoring is expected to guide future RSWMP monitoring, the research schedule has been revised. Monitoring will be conducted from March 1, 2012 to February 28, 2013, with the final technical report expected for release in June 2014 (see Table 1).

Table 1.

SNPLMA-funded Catchment Validation Study research schedule.

Milestones/Deliverables

Original

Start Date

Revised

Start

Date

Task 1. Catchment selection, Monitoring plan and PLRM model development

Task 2.1 Road maintenance strategy development with jurisdiction partners

Task 2.2 Road maintenance strategy and reporting summary

Task 3. Catchment and event monitoring and data collection

Task 4. Data management and analysis; PLRM simulations and hypothesis testing

Task 5.1: Prepare quarterly progress reports

Task 5.2 Draft Technical Report

Task 5.3 TAC meeting, comments and feedback

Task 5.4 Final Technical Report

8/1/2011

8/1/2011

9/1/2011 9/1/2011

10/1/2011 3/1/2012

10/1/2011 3/1/2012

Original

End Date

9/30/2012

1/31/2013

9/31/2013

Revised

End Date

8/1/2011 12/30/2011 2/28/2012

8/1/2011 12/30/2011 3/31/2012

3/31/2013

2/28/2013

3/31/2014

7/1/2011 9/1/2011

10/1/2011 3/1/2012

7/31/2013

7/31/2013

3/31/2014

1/31/2014

1/1/2013 7/1/2013 9/31/2013 3/31/2014

4/1/2013 10/1/2013 12/30/2011 6/30/2014

Table 2.

Seasons as defined in Lake Tahoe Municipal NPDES permit (LRWQCB 2011).

Season (months)

Summer/Fall

Winter

Start

August 1

January 1

End

December 31

February 28

Late Winter/Early Spring

Spring/Summer

March 1

May 1

April 30

July 31

RESEARCH GOALS AND OBJECTIVES

The following are the research goals and objectives of the SNPLMA-funded research.

GOAL

This research will build upon the initial dataset produced by the US ACE-funded research to validate the critical tool hypotheses by providing a controlled urban catchment study that strategically characterizes the actual road maintenance practices and measures observed land use and catchment conditions, flow and water quality loading.



OBJECTIVES

1.

Improve our understanding of the factors influencing pollutant loading from urban catchments and temporal variation associated with hydrologic, land use, and treatment BMP conditions.

2.

Provide scientifically valid and reliable data that quantifies the effectiveness of road maintenance practices in the Tahoe Basin, including an assessment of cost-effectiveness.

3.

Working with local jurisdictional partners (City of South Lake Tahoe and Washoe County), document relevant aspects of road and treatment BMP maintenance actions to better assess their relationship to monitoring data and modeling results.

4.

Strategically instrument catchments to collect high resolution water quality data to characterize catchment loading and treatment BMP performance, and test these against pollutant loading estimates generated using the current stormwater tools for the TMDL program.

5.

Conduct modified PLRM simulations on event, seasonal and annual scales and compare to monitoring information to investigate the effectiveness of PLRM algorithms for integrating pollutant generation and treatment BMP performance as average annual loads. If warranted, develop recommendations for improving PLRM based on observed catchment scale hydrology and water quality.

6.

Statistically evaluate the sensitivity of key factors expected to influence catchment water quality. Key factors may include seasonal and event meteorologic characteristics, road maintenance practices, road attributes, catchment land use distribution, road condition, treatment BMP design parameters, treatment BMP condition, maintenance practices, etc.

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RESEARCH APPROACH

While the research approach is unchanged from the US ACE Pilot Catchment Study , a brief overview is provided below.

ROADWAY CONDITION

Catchment pollutant loads are the integrated signal of pollutant sources and stormwater volumes within the catchment. The PLRM and Road RAM are based on the primary assumption that not all surfaces of the same land use type will have the same influence on water quality downslope. Both land use type (primary road, secondary road, single family residential, commercial/institutional, etc.) and land use condition (poor, degraded, fair, acceptable, or desired) influence measured water quality of the catchment. Roads are assumed to be a significant source of the pollutants of concern, particularly TSS and FSP generated from road abrasive applications, erosion of unprotected road shoulders and an increase in the fine sediment particle (FSP) fraction due to pulverization by vehicular traffic. Even in mixed land use catchments, the road network often comprises the majority of directly connected impervious area (DCIA) and routes the majority of stormwater through urban areas to receiving waters. Existing research continues to indicate that the greatest achievable urban water quality improvements can be accomplished with improved road maintenance strategies (2N and NHC 2010a,

2010b, 2N et al. 2010c, 2N and NHC 2011). The 2NDNATURE research team will work collaboratively with the jurisdiction partners to define, characterize and track the specific range of road maintenance practices that will be included in the research, and the correlation between road maintenance practices, Road RAM road condition observations and catchment water quality (described below) will be tested.


SNPLMA Round 11 Catchment Validation Study: Monitoring Plan

CATCHMENT FSP LOADING

p.

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Each urban catchment outlet has been strategically instrumented to provide continuous flow, continuous turbidity and targeted water sample collection for analytical analyses. The priority pollutant of concern for this research is fine sediment particles (FSP; < 16um), though analyses of total suspended sediment (TSS), total phosphorous (TP) and the biologically available, soluble reactive phosphorous (SRP), may be included as resources allow. Road conditions will be monitored throughout the water year using Road RAM, targeting evaluations prior to targeted runoff events. Discrete water quality samples at the outlet of the catchment will be obtained to represent a range of runoff event types (winter rain, rain on snow, summer thunderstorm and snowmelt) and to develop FSP to turbidity rating curves that represent the range of hydrograph conditions

(rising limb, peak flow and falling limb) within each catchment. The continuous hydrologic and turbidity record will allow the research team to extrapolate the pollutant loads for sampled events and to reasonably estimate seasonal and annual pollutant loading.

COMPARISON TO PLRM SIMULATIONS

The event specific meteorology and land use condition observations will be loaded into the catchment specific

PLRM models to create event based PLRM model estimates to compare to measured event, seasonal and annual loads. PLRM estimates are conducted on an average annual basis over an 18-yr simulation; however the underlying SWMM hydrology module can be run on any time scale. The catchment condition, water quality and treatment BMP condition dataset over a complete water year will provide the first real datasets necessary to validate PLRM predictions. Model simulations will be conducted on selected event, seasonal and annual time scales. Deviations between predicted and observed pollutant loads will be investigated using sensitivity analyses to identify potential improvements to PLRM algorithms. The results of the simulations will be used to investigate the predictive power of using land use conditions in PLRM and to evaluate the effectiveness of current algorithms using Characteristic Runoff Concentrations (CRCs) to estimate average annual pollutant loads. The continuous annual catchment hydrology and observed event specific loads will be used to formulate a scaling approach to estimate annual catchment loading based on a select number of discrete monitored events. The scaling technique will be extremely useful to advise jurisdictions and RSWMP on how to design event monitoring data collection and analysis for use in future validation of annual average loading estimates from

PLRM.

The experimental design of this research will also provide data to conduct a sensitivity analysis of the catchment water quality signal to respective road maintenance practices and associated road conditions. Knowing that road condition varies seasonally due to significant shifts in anthropogenic sources and both natural and anthropogenic sinks of pollutants on roads, statistical sensitivity analyses can be conducted to evaluate the influence road conditions have on catchment water quality. The detailed records of the specific road maintenance practices implemented over the same time frames will allow powerful evaluations of how road maintenance practices can improve urban catchment pollutant loading.

DATA COLLECTION STRATEGY

SITE SELECTION

The Osgood catchment (Figure 1) was selected as the pilot catchment for research using US ACE funds. The

SNPLMA Round 11 funding allowed for the expansion of catchment monitoring to 2 additional catchments: a


SNPLMA Round 11 Catchment Validation Study: Monitoring Plan second catchment within CSLT jurisdiction and one catchment within Washoe County. 2NDNATURE personnel met with public works engineers from both jurisdictions to select catchments that met the following criteria: p.

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1.

The catchment outlet was a direct outfall to Lake Tahoe, ensuring that monitoring can directly measure pollutant loading to the lake and are likely to be used in the future as RSWMP long-term monitoring locations.

2.

These locations are a high priority in the jurisdiction’s overall strategy reduce pollutant loading to Lake

Tahoe, and either are or in the near future will be registered catchments in the Crediting Program.

Based on these criteria and with input from the jurisdictions, the research team selected the Pasadena catchment in South Lake Tahoe, CA (Figure 2) and the Central Incline Village catchment (Figure 3) in Washoe

County.

The Pasadena catchment in South Lake Tahoe, CA (Figure 2) is predominantly residential and secondary road land uses in the

Al Tahoe neighborhood. The catchment outlet is a 36” culvert that drains directly in to Lake Tahoe (see photo at right). A water quality improvement project was recently completed in this catchment in 2010, including the installation of infiltration-based BMPs along the road shoulders to reduce stormwater runoff from the residential catchment and a

Contech Stormfilter cartridge filter at the base of the catchment to treat catchment pollutant loads.

The Central Incline Village catchment (Figure 3) in Incline

Village, NV drains directly to Lake Tahoe through a small earthen ditch (see photo at right) near the intersection of

Lakeshore and Village Boulevards. This catchment includes both primary high risk (Highway 28) and secondary high risk

(Village Boulevard) roads, and a future WQIP is planned for

2013, with potential improvements including construction of source control BMPs to stabilize bare shoulders and channels, installation of treatment vaults and sediment basins to capture FSP in the stormwater runoff, and the purchase of an

Epoke spreader and high efficiency vacuum sweeper to

Photos of the outfalls of Pasadena (top) and Central Incline Village catchments

(bottom) reduce the amount of FSP generated from the urban road surfaces. Currently a Vortechnics treatment vault treats the initial catchment runoff at the base of Village

Boulevard; however anecdotal evidence indicates this SWT has a minimal treatment effect at reducing FSP pollutant loads.

INSTRUMENTATION

High resolution (15-minute) pressure transducers and turbidity sensors (Table 3) were installed in Pasadena and

Central Incline Village catchments in January 2012 (see photos below) and will be calibrated during runoff events throughout February to ensure data will be collected properly and consistently once the late winter/early spring season commences on March 1. Depth will be converted to flow using the standard equation for the flume and confirmed by spot flow measurements throughout the monitoring season. Turbidity will be converted to FSP using the turbidity to FSP rating curve.



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Monitoring instruments installed in Pasadena outlet culvert (left) and Central Incline

Village outlet channel (right).

Table 3 . Instrumentation installed at each catchment outlet.

Catchment

Outlet Type / Flow constraint

Pressure

Transducer

Turbidity Sensor Installation Date

Osgood Notch weir

Campbell

Scientific OBS -3

February 2011;

Pressure Transducer replaced Jan 2012

Pasadena

Central Incline

Village

4’ culvert with Palmer

Bowlus flume 1

Small channel with H flume

Campbell

Scientific

CS450

FTS DTS-12

January 2012

January 2012

1 Flume is property of Desert Research Institute (DRI) and on loan from DRI for the length of this monitoring research.

SAMPLE COLLECTION

During stormwater runoff events, field personnel will collect grab samples and analyze for turbidity in the field using Hach 2100P portable turbidimeter to calibrate the instrument turbidity measurements. Samples measuring over 50ntu in the field will be submitted to WETLAB Laboratory for TSS and particle grain size analysis to continue to refine the current turbidity to FSP relationship. Following the collection of 20 samples within the range of 50-100ntu, the threshold will be raised to 100ntu to remain cost-effective and to target the existing data gaps at the higher end of the turbidity to FSP rating curve. A subset of the TSS/FSP samples will also be submitted to the laboratory for TP and SRP analyses to improve our understanding of the fate and transport of phosphorous species in urban stormwater. Again, the analytical goal will be obtain a range of expected TP and

SRP concentrations at the site and turbidity criteria will be used to identify samples that may have relatively higher TP and SRP concentrations. The water quality samples submitted to the laboratory will be limited to a total of 90 TSS and FSP samples and 60 TP and SRP.

DATA MANAGEMENT & FIELD QAQC

During all site visits, field personnel will manually measure the stage using a stadia rod or tape measure to verify the depth measurements recorded by the pressure transducers. If runoff is occurring, field personnel will (1) conduct a manual flow measurement to verify the depth to flow conversion equations and (2) collect a surface water grab sample for turbidity analysis for comparison to the sensor readings. Site conditions will be


SNPLMA Round 11 Catchment Validation Study: Monitoring Plan documented with photographs of the instrumentation, catchment outlet, etc, and detailed field notes will be recorded, including date, time, weather conditions, etc. p.

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All collected research data will be managed in a Microsoft Access relational database following data QA/QC for accuracy and completeness. Instruments will be downloaded on a monthly basis, calibrated using field spot measurements, and checked for inaccuracies. Lab analysis results will be submitted electronically by WETLAB, checked for data quality and completeness, and verified against the chain of custody record.

DATA ANALYSIS

Given the alpine climate and freeze/thaw cycles of surface water in the Tahoe Basin during the winter months, instrumentation failure is highly likely. Field personnel will regularly maintain the instruments to reduce the length of potential data gaps; however missing data will occur. Time periods will be identified where there is high confidence in the quality of instrument time series data. These time periods will be modeled in SWMM to provide a direct comparison of PLRM predictions and observed catchment FSP concentration time series, discharge and loads for discrete time periods.

LITERATURE CITED

2NDNATURE (2N), Northwest Hydraulic Consultants (NHC), and Environmental Incentives (EI). 2009. Best

Management Practice Maintenance Rapid Assessment Methodology (BMP RAM) Technical Document, Tahoe

Basin. Final Document. Prepared for Army Corps of Engineers, Sacramento District. September 2009. Complete documentation, users manual and tool available for download at http://www.swrcb.ca.gov/rwqcb6/water_issues/programs/tmdl/lake_tahoe/index.shtml

.

2N and NHC. 2010a. PLRM v1 Focused Stormwater Monitoring to Validate Water Quality Source Control and

Treatment Assumptions Technical Report. Final Document. Prepared for Army Corps of Engineers, Sacramento

District. March 2010.

2N and NHC. 2010b. PLRM Refinement Monitoring, Phase II Monitoring Plan. Final Document. Prepared for USFS

Pacific Southwest Research Station. July 2010.

2N, NHC, and EI. 2010c. Road Rapid Assessment Methodology (Road RAM) Technical Document, Tahoe Basin.

Final Document. Prepared for the California Tahoe Conservancy and Nevada Division of Environmental

Protection. November 2010. Complete documentation, users manual and tool available for download at http://ndep.nv.gov/bwqp/tahoe8.htm

.

2N and NHC. 2011. Pilot Catchment Validation and Testing of Existing Tahoe Basin Stormwater Tools. Final Data

Collection Plan. Prepared for Army Corps of Engineers, Sacramento District. April 2011.

2N and NHC. 2012. Focused Stormwater Quality Monitoring to Inform PLRMv1 Assumptions & Evaluate

Predictive Capabilities Technical Report. Prepared for Army Corps of Engineers, Sacramento District and USFS

Pacific Southwest Research Station. Expected April 2012.

Lahontan Regional Water Quality Control Board (LRWQCB) and Nevada Division of Environmental Protection

(NDEP). 2009. Lake Clarity Crediting Program Handbook: for Lake Tahoe TMDL Implementation v0.99.

Prepared by Environmental Incentives, LLC. South Lake Tahoe, CA. September 2009. http://www.swrcb.ca.gov/rwqcb6/water_issues/programs/tmdl/lake_tahoe/



LRWQCB and NDEP. 2010. Final Lake Tahoe Total Maximum Daily Load. November 2010. http://www.swrcb.ca.gov/rwqcb6/water_issues/programs/tmdl/lake_tahoe/docs/tmdl_rpt_nov2010.pdf

p.

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LRWQCB. 2011. Lake Tahoe Municipal NPDES Permit. December 2011. http://www.swrcb.ca.gov/rwqcb6/water_issues/programs/tmdl/lake_tahoe/npdes.shtml

Northwest Hydraulic Consultants (NHC), Geosyntec Consultants, and 2NDNATURE. 2009. Pollutant Load

Reduction Model (PLRM) Model Development Document. Prepared for Tahoe Basin Storm Water Quality

Improvement Committee. South Tahoe Basin, CA. October 2009. Complete documentation, users manual and tool available for download at http://www.tiims.org/TIIMS-Sub-Sites/PLRM.aspx

.



FIGURES

Figure 1. Osgood Catchment Location Map

Figure 2. Pasadena Catchment Location Map

Figure 3. Central Incline Village Catchment Location Map p.

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LEGEND

LEG END

Instrument Location

Roads

Catchment

ST

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FO

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Figure 1: Osgood Catchment Location Map

0

Feet

300 600 1,200

LEGEND

LE GE ND

Instrument Location

Roads

Catchment

LAKEVIE

W AVE

MERCED

AVE

ALAMED

SAN JOS

A

S

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E AVE

A AVE

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GOLD TIP AVE

A

STAR LAKE AVE

CAVE ROCK AVE

Figure 2. Pasadena Catchment Location Map

0

Feet

150 300 600

LEGEND

LEG EN D

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Roads

Catchment

DO

NN

A D

R

NORTHWOOD BLVD

ALDER AVE

TAHOE BLVD

N ENTERPRISE

OR

IOL

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AY

TANAGER S

T

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LUPIN LN

FREEL'S

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R

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LVD

VIL

LA

G

E B

JUA

NIT

A D

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LV

D

Figure 3: Central Incline Village Catchment Location Map

0

Feet

300 600 1,200

Catchment Validation Study Final Monitoring Plan February 2012

Catchment Validation Study

Final Monitoring Plan