Research Proposal; SNPLMA Round 9 Theme: 2A
page 1
Priority Urban Stormwater Monitoring to Directly Inform the Pollutant Load Reduction Model (PLRM)
Project Abstract
The initial version of the Pollutant Load Reduction Model (PLRM) is currently in development by
northwest hydraulic consultants (nhc), 2NDNATURE, and Geosyntec Consultants through grants provided
by the US Army Corps of Engineers (USACE) and the Nevada Department of Environmental Protection
(NDEP). The objective of the PLRM is to provide Lake Tahoe resource managers with a tool to evaluate
pollutant load reduction alternatives for urban storm water quality improvement projects. The research
team submitting this proposal is the PLRM development team and the SNPLMA research results will
directly improve confidence in PLRM loading estimates, particularly for very fine sediment1 loads for
Lake Tahoe urban areas. The PLRM estimates pollutant loads using two primary water quality functions,
Characteristic Runoff Concentrations (CRCs) and Characteristic Effluent Concentrations (CECs). A CRC
is a representative concentration for a pollutant of concern in runoff from a specific urban land use and
associated condition. A CEC is a representative effluent concentration for a pollutant of concern from a
specific storm water treatment BMP type (SWT). When combined with continuous runoff hydrology from
the PLRM, CRCs and CECs provide a representative estimate of average annual pollutant loading and a
relative comparison of average annual pollutant loading among alternatives. The greatest limitation in
the initial version of the PLRM (expected to be released in early 2009) is the lack of very fine sediment
data (<20μm) to inform CRCs and CECs. The funding for research in this proposal will be highly costeffective by 1) building on the research team’s experience with PLRM development, 2) building on
previous analyses of existing data to create the PLRM CRC and CEC database, and 3) augmenting an
initial phase of urban stormwater data collection to inform PLRM currently being initiated for the USACE
(2008). The goals of this research are to 1) provide improved scientific basis to estimate pollutant CRCs
(focusing on very fine sediment) and their variability with land use conditions and 2) estimate very fine
sediment CECs for typical Lake Tahoe SWTs and their variability with fundamental design parameters.
This research addresses two of the SNPLMA Water Quality subthemes (2A and 2B). The CRC research
will address both Water Quality subthemes 2A and 2B and the CEC research will primarily address Water
Quality subtheme 2A, all of which will directly inform PLRM data gaps.
Justification Statement
The research team submitting this proposal is the PLRM developer and has a very detailed and practical
understanding of the specific water quality data needed to improve the water quality functions of the
PLRM. Thus, the research team has the ability to monitor and model pollutant generation from varying
land use conditions and storm water BMP types, develop recommendations formatted for the PLRM
database, and understand the implications of improved input data on the overall function of the PLRM.
CRC (Characteristic Runoff Concentrations)
The PLRM provides a function to decrease the pollutant generation from a land use when the land use
condition improves. Condition is defined as the existing state of a land use relative to the pollutant
generation risk during a subsequent storm. A wide range of pollutant source controls are implemented
on urban land uses (commercial, residential, roads) with the intention of improving condition and
reducing the pollutant generation risk. In the PLRM, the relative condition of urban land uses within a
catchment is correlated to a characteristic runoff concentration (CRC) for pollutants of concern impairing
Lake clarity. A CRC is a representative concentration for a pollutant of concern in runoff from a specific
urban land use and associated condition. When combined with continuous runoff hydrology from the
PLRM, CRCs provide a representative estimate of average annual pollutant loading for specific land use
conditions. PLRM users define the condition of a land use based on the integration of key physiographic
and disturbance characteristics of the land use, pollutant source controls applied to the land use,
and the effectiveness of pollutant recovery efforts. Representative CRCs for the range of existing land
use conditions within Lake Tahoe are imperative to improve the validity of the PLRM pollutant loading
estimates from urban catchments.
1
The RFP defines fine sediment as <63 μm and very fine sediment as <20 μm. While fine sediment <63 μm will be evaluated by this research, the majority of the scope has been formulated to address the fate and transport of very fine sediment in Lake Tahoe urban areas.
Consequently, the term “very fine sediment” is used in the proposal to be consistent with the definition used in the RFP.
2NDNATURE, LLC
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
page 2
CEC (Characteristic Effluent Concentrations)
The PLRM provides a function to estimate the performance of a storm water treatment BMP (SWT) by
assigning a characteristic effluent concentration (CEC) depending on the SWT type and fundamental
design parameters. For the purposes of the proposal, an SWT is defined as a storm water treatment BMP
that reduces pollutants of concern from a concentrated storm water flow path. Examples of SWTs include
detention basins, wet ponds, media filters, etc. PLRM uses a CEC to represent the effluent concentration
typically achieved by an SWT. When combined with continuous runoff hydrology from the PLRM, CRCs
provide a representative estimate of average annual pollutant loading at the outlet of an SWT.
Existing PLRM CRCs and CECs
Currently CRCs and CECs in the PLRM are based upon existing event mean concentration (EMC)
data from Lake Tahoe water quality monitoring studies2 and the International BMP Database (www.
bmpdatabase.org). Confidence in CRCs currently being developed for the PLRM database is limited
because 1) existing Tahoe Basin storm water data predominantly quantify runoff quality from tributary
areas that contain a mixture of land uses, 2) existing storm water data is not linked to land use condition
of the contributing catchment at the time of monitoring, and 3) minimal very fine sediment storm water
data exists at all. Confidence in CECs currently being developed for the PLRM database is limited
because 1) minimal very fine sediment data are available to define SWT performance and 2) minimal
information is available to link removal of very fine sediment to fundamental SWT design parameters
that influence treatment performance (e.g. hydraulic residence time, outlet design, etc.).
The limitations listed above lead to considerable uncertainty in PLRM load estimates, particularly for
very fine sediment. Recognizing that this current uncertainty is based on limited scientific data and
understanding of fine sediment in urban storm water, the PLRM development approach uses conceptual
models that reflect the current understanding of important pollutant generation and storm water
treatment processes combined with a flexible database structure. The PLRM framework allows for new
scientific information to be readily updated into the PLRM water quality functions. Increased accuracy
and reliability of PLRM load estimates depends on data collection and analysis specifically designed to
better inform key model input parameters (e.g., the CRC and CEC database).
The primary subtheme addressed by this research is Water Quality 2A. Effectiveness of urban and
roadway BMPs in removing fine sediment from storm water runoff with monitoring focusing on
quantitatively constraining and testing the treatment performance of Lake Tahoe SWT types with respect
to the primary pollutant of concern in the Lake Tahoe Basin, very fine sediment. However, the research
will effectively address the second subtheme, Water Quality 2B. Sources, characterization and transport
of fine particles from urban land uses, by directly expanding and augmenting an initial phase of land
use condition monitoring currently being initiated by the USACE (2008). The USACE has authorized the
research team (2NDNATURE and nhc) to proceed with a limited data collection effort that will collect
preliminary data to test and define road condition and CRC correlations and very fine sediment removal
from 2 to 3 detention basins (one SWT type). The USACE effort is limited in scope and monitoring
duration (December 2008 through June 2009). This SNPLMA research proposal would build directly on
the USACE effort by expanding the spatial application and duration of land use condition sampling and
increasing the SWT types monitored.
Concise Background and Problem Statement
Background and problem statements described below provide additional detail to support the above
research justification for improving estimates of CRCs and CECs focused on very fine sediment.
2
Lake Tahoe event-specific water quality monitoring data has been compiled and integrated from a variety of sources including UC Davis,
DRI, 2NDNATURE, NDOT, Caltrans, El Dorado County and others. Detailed citations of the existing datasets are included in the References
section of this proposal.
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321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
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Characteristic Runoff Concentrations (CRCs)
Most storm water data collection and analyses for Lake Tahoe TMDL development have assumed
the primary determinant of runoff quality is land use distribution. While several datasets of urban
catchment water quality have been collected in the Basin over the last 10 years (Gunter 2007,
2NDNATURE 2006, 2008, Cal Trans 2006, etc.), the quantitative impact of land use condition on
water quality has not been rigorously evaluated. The preliminary analysis of the Basin’s water quality
monitoring datasets compiled by the PLRM developers (nhc, 2NDNATURE and Geosyntec) suggests that
pollutant generation must be characterized by the condition of the land uses in the urban catchment
and not solely by the land uses present. Using urban roads as an example, Figure 1 illustrates the
conceptual integration of slope, traffic density, the degree of road shoulder stabilization, and practices
used to apply and recover pollutants accumulated to determine urban road condition in Lake Tahoe.
The PLRM uses the following approach to compute pollutant generation in an urban drainage catchment:
Step 1 - For each land use present in a urban catchment, the potential pollutant generation is
characterized based on key physiographic and anthropogenic factors.
Step 2 - Pollutant source controls and associated recovery actions for each land use are characterized,
which reduces the potential pollutant generation defined in Step 1.
Step 3 - The land condition developed in Steps 1 and 2 is correlated to a CRC defined in the PLRM
database.
Step 4 – Pollutant loads for land uses present in the urban drainage catchment are integrated as the
product of land-use specific CRCs and runoff volumes calculated in the PLRM.
With the initial version of the PLRM planned for release in early 2009, a thorough data collection
effort is needed to better quantitatively relate land use conditions to CRCs, with a heightened need to
increase confidence in estimates of very fine sediment loading in the PLRM.
Characteristic Effluent Concentrations (CECs)
Existing SWT performance data focuses on total suspended sediment and nutrient species, leaving
a critical data gap in understanding SWT performance for removing fine and very fine sediment
(2NDNATURE 2008). Even the International BMP Database (www.bmpdatabase.org) has minimal data
about SWT performance to treat very fine sediment. Because SWTs used in Lake Tahoe commonly
rely on settling, particle size likely plays an important role in SWT performance for very fine sediment
removal. Research indicates that Lake clarity is highly influenced by particle numbers and that
particle number distributions are highly skewed towards particle sizes smaller than 20 μm (Lake Tahoe
LRWQCB 2007a). Therefore, the reduction and/or removal of very fine sediment in storm water is
crucial to achieving Lake Tahoe’s TMDL clarity goals. Settling theory as a conceptual model for particle
removal becomes more complex for finer particles and local hydraulic processes (mixing, turbulence,
wind effects, adsorption, filtering) become more important. Reasonable doubt exists regarding the
performance of typical SWTs employed in the Basin to remove very fine sediment, yet little to no data
exists to support our assumptions. A better understanding of SWT performance could fundamentally
change the approach to SWT selection and design in the Basin as well as improve the current PLRM
assumptions for SWT treatment capabilities.
Figure 2 illustrates the PLRM approach to compute the performance of an SWT. The conceptual water
quality modeling approach linking SWT type to treatment performance (defined by a CEC) is supported
by the literature and available data. However, research is needed to better relate very fine sediment
removal for multiple types of SWTs deployed in the Basin to understand which SWTs successfully treat
fine sediment in storm water and to increase confidence in estimates of very fine sediment loading in
the PLRM.
Hypotheses, Goals and Objectives
Hypotheses
1. CRCs (particularly for very fine sediment) of specific land use conditions can be correlated with
increased certainty through focused land use condition water quality monitoring.
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Research Proposal; SNPLMA Round 9 Theme: 2A
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2. Water quality data collected from specific land use conditions will significantly improve the predictive
capability of PLRM pollutant generation calculations from urban catchments.
3. SWT performance for treating very fine sediment is related to key design parameters associated with a
particular SWT type.
4. Water quality data collected from SWTs typically deployed in the Tahoe Basin will significantly improve
the predictive capability of PLRM storm water treatment calculations for fine sediment reduction.
Goals
Improve the scientific basis to: 1) estimate pollutant CRCs (focusing on very fine sediment) and their variability
with land use conditions, and 2) estimate very fine sediment CECs for typical Lake Tahoe storm water treatment
BMPs (SWTs) and their variability with fundamental design parameters.
Objectives
1. Collect data from discrete urban land use conditions in a controlled and comparable manner to
improve understanding of how variable land use conditions generate very fine sediment, and to a
lesser extent, nutrients.
2. Identify key SWT design parameters for very fine sediment removal and collect data from SWTs
deployed in the Basin to link very fine sediment treatment performance to variability in these
parameters.
3. Build upon existing data and research, while working within the modeling framework of PLRM, to fill
critical water quality data gaps.
4. Collaborate with academic researchers in data and sample sharing for their development of
appropriate numeric conversions from very fine sediment concentration and loads to number of
particles.
Approach, Methodology and Location of Research
Location of Research
Data collection will be conducted in urban areas that represent the range of land use conditions and
SWT types typical of Lake Tahoe. The sites will be strategically selected to collectively meet all of the
objectives in a cost effective and efficient manner. Land use condition sampling sites will primarily
be located in either El Dorado or Placer County urban areas to build upon previous and ongoing data
collection, PLRM development and PLRM validation efforts. Additional sites may be located outside
of these jurisdictions to ensure the land use sites are collectively representative of Basin conditions.
The SWT sampling will likely occur at previously and/or currently monitored SWTs due to the sampling
strategy and instrumentation efficiencies of reoccupying successfully monitored SWTs.
Approach and Methodology
The research team (2NDNATURE and nhc) contracted with the USACE (2008) to conduct an initial phase
of storm water data collection to fill critical PLRM data gaps on October 22, 2008 (the week SNPLMA
Round 9 proposals were due). The scope of the USACE effort is limited and data collection efforts will
end in June 2009. This SNPLMA research will directly augment the recently initiated USACE efforts by
building upon the USACE Monitoring Plan, extending monitoring duration and sampling stations. The
SNPLMA research will benefit from the lessons learned over the first 8 months of data collection and
ultimately result in greater efficiency of resource expenditures to maximize data collection and analyses.
The research team has exceptional knowledge of the challenges of storm water data collection within
the Basin. 2NDNATURE has successfully completed numerous complex storm water monitoring studies
over the past 6 years by employing a variety of innovative and cost-effective data collection techniques
over a wide range of site conditions. DRI’s participation on the research team will ensure techniques
are consistent with future Lake Tahoe Regional Storm Water Ambient Monitoring Program (RSWAMP)
methods.
Below are preliminary sampling approaches and techniques that may be used to meet the goals and
objectives of this research; the final strategy will be outlined in the SNPLMA Monitoring Plan (Task
1). The project budget has been developed to allow for a wide range of data collection strategies
2NDNATURE, LLC
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
page 5
that include a combination of low cost and high-resolution data collection options to meet the study
objectives.
Sampling Approach - (CRCs) Characteristic Runoff Concentrations
Five key land uses will be studied in this proposal: primary roads, secondary roads, single family
residential, multi-family residential, and commercial/industrial. Data already exists for 100% veg_turf
land use (2NDNATURE 2007). Public impervious surfaces will be a priority as these are the lands where
urban jurisdictions have the greatest opportunities to implement water quality improvement strategies.
Land use condition can vary on very short time scales and is dependent upon a multitude of factors
(see Figure 1 for an example of the factors assumed to influence urban road condition). Land use
condition will be documented using standardized observations prior to either controlled sampling or
targeted runoff event sampling using Road and BMP Rapid Assessment Monitoring (RAM) protocols
currently under development by 2NDNATURE and nhc. The RAM tools provide a simple and standardized
technique to rapidly evaluate and track the condition of an urban land use. The integration of PLRM,
RAM and detailed water quality data collection will greatly improve the correlations between land use
condition and expected CRC and ultimately improve the validity of PLRM results.
Monitoring site instrumentation will be constructed, purchased and installed according to the protocols
outlined in the SNPLMA Monitoring Plan (Task 1). The data collection strategy will sample runoff from
small tributary areas comprised of a single land use over a range of conditions meeting the factors
described in the PLRM CRC approach. Sampling will be conducted using a combination of low cost
passive and more elaborate high-resolution techniques to maximize benefits of available resources.
While high-resolution, flow-weighted sampling may provide more complete representative event
mean concentrations by collecting samples throughout a storm hydrograph, cost-effective passive
sampling techniques allow for sampling on a greater spatial scale throughout a range of land uses
and respective conditions. First flush chemical composition is assumed to be elevated relative to the
event mean concentration (Bertand-Krajewski et al.1998), however any error or variability across sites
and event types associated with runoff event definitions, number of samples collected, and timing of
sample collection within the hydrograph is eliminated. This increases confidence that the differences
in pollutant concentrations across sites are attributable to differences in site conditions. It is currently
anticipated that 10-15 permanent sampling stations will be installed and operated to provide eventbased water sampling results from a range of representative land use conditions. Event-based sampling
will likely be augmented with controlled urban runoff simulations3 - simple and repeatable techniques to
apply water on a specific urban surface area in a consistent manner. The runoff simulation techniques
will be developed and tested during the USACE (2008) initial land use condition sampling.
Sampling Approach - (CECs) Characteristic Effluent Concentrations
The primary objective of SWT sampling is to expand our understanding of the fate and transport of very
fine sediment in stormwater introduced to a SWT. Linking high-resolution sampling with key SWT design
parameters will increase our ability to predict representative CECs from a range SWT types. SWTs to be
assessed in this study include detention basins, wetlands/wet ponds, and media cartridge filters. Sand
traps may also be monitored at a reduced level, with the objective to better understand the quantitative
difference between input and output concentrations and loads of these popular source control features.
Design parameters, such as aspect ratio, volume capacity, inlet and outlet design, vegetation density
and distribution, flow cell characteristics, infiltration capability, etc. will be documented for selected
SWTs. The PLRM design team believes these parameters likely influence the performance of very fine
sediment removal and therefore will be considered during data collection and data analysis.
The research team will evaluate SWTs currently deployed in the Basin and strategically select SWT
monitoring sites to represent a range of key design parameters. Ideally, at least 2 of each SWT type are
3
The controlled runoff techniques, currently in preliminary development by El Dorado County, will apply known volumes of water at a
constant intensity to the selected surfaces and collect water samples directly downslope of the land use being evaluated. While these techniques may not be completely representative of the intensity and duration of rainfall and runoff from every natural storm event, maintaining consistency of water application rates across the land use as well as consistent sampling techniques will provide reliable quantitative
comparisons of water quality as a function of land use condition.
2NDNATURE, LLC
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
page 6
instrumented for hydrologic and water quality monitoring. The appropriate instrumentation and sampling
techniques will be tailored to SWT type and site opportunities and constraints. Where appropriate,
previously or currently instrumented and monitored SWTs will be occupied to improve efficiency,
minimize sampling complications, and build upon previous data sets. Multiple event types (rain on snow,
thunderstorm, rain, and snowmelt) will be sampled at each site to evaluate SWT performance under a
range of hydrologic conditions and influent qualities, improving our confidence in the representative
CECs in PLRM. The SWTs selected will be instrumented using either high-resolution instrumentation
and/or passive sampling techniques at the inlet and outlet to ensure both effluent quality and total
load reduction estimates can be determined. SWT instrumentation may also include continuous stage
recorders within the SWT to calculate cost-effective water budgets and hydrologic loading estimates. If
available, turbidity meters may also be employed at strategic locations to explore potential correlations
between very fine sediment concentration and turbidity.
2NDNATURE and nhc are currently developing a BMP Rapid Assessment Methodology (funded by USACE)
to quickly assess temporal variations in SWT condition assumed to influence the SWT’s water quality
treatment performance. The condition of the SWTs monitored will be continually documented (using the
USACE protocols) and used to qualitatively compare the anticipated treatment capability of the SWT
to the very fine sediment data collected. The initial version of PLRM does not incorporate the water
quality impacts as SWT condition declines (i.e., need for maintenance increases), but the addition of
SWT condition with water quality performance observations could improve our understanding of SWT
condition and allow for the potential expansion of PLRM in future versions.
In addition to monitoring, the research will include development of numerical models as a method to
validate and extend data related to SWT performance under variable hydraulic conditions. SWT hydraulic
models will be developed to relate very fine sediment removal to fundamental design parameters such
as hydraulic loading. Modeling will be used to: 1) develop and test predictive relationships between
design and performance and, if successful, 2) extend data sets to estimate CECs for a range of
hydrologic and hydraulic conditions.
Analytical Approach
The priority pollutant of concern for PLRM and this research is very fine sediment (<20μm), though
PLRM does include estimates of total suspended sediment (TSS), total phosphorus (TP), soluble reactive
phosphorus (SRP), total nitrogen (TN), and dissolved inorganic nitrogen (DIN). All water quality samples
collected for this research will be analyzed for TSS and particle size distribution (PSD) with the following
μm size breaks: 1, 10, 20, 63, 100 and 1000. Due to cost and the greater availability of existing nutrient
water quality data, approximately 20% of the total samples collected will be analyzed for both sediment
and nutrient constituents. All of the above pollutants are expressed as mass loads in the PLRM output,
including very fine sediment. Other Lake Tahoe scientists from TERC and DRI are currently working on
“particle count converters” to translate detailed PSD data to number of particles. The research team
for this proposal includes Dr. Alan Heyvaert of DRI to provide technical direction and DRI laboratory
analyses on the storm water samples collected. All water quality samples collected under this research
will be available for further particle characteristic analysis to improve the ability of the empirical tools to
convert very fine sediment mass to # of particles.
Relationship of Research to Previous Relevant Research, Monitoring, and/or Environmental
Improvement Efforts
The proposed research will inform and/or build upon the following Lake Tahoe efforts:
• Lake Tahoe Total Daily Maximum Load (TMDL)
• Pollutant Load Reduction Model (PLRM) funded by USACE
• Lake Tahoe Lake Clarity Crediting Program
• USACE (2008) Initial stormwater quality sampling to inform PLRM
• Operations and Maintenance Rapid Assessment (O&M RAM) development funded by the USACE
• Roads Rapid Assessment Methodology (Roads RAM) development funded by the CTC
• Performance of BMPs4, data base development lead by DRI and funded by SNPLMA Round 7.
4
http://www.fs.fed.us/psw/partnerships/tahoescience/bmp_performance.shtml led by DRI, assisted by nhc, Geosyntec and 2NDNATURE.
2NDNATURE, LLC
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Research Proposal; SNPLMA Round 9 Theme: 2A
page 7
Strategy for Engaging with Managers
The research team will coordinate data collection efforts with the Engineering Departments of El Dorado
County and Placer County. The research team already has strong working relationships with each of
these entities, and this funding will further improve the ability of the PLRM team and these two local
jurisdictions to collaborate on valuable applied data collection efforts. The PLRM PAC members have
been intimately involved in the model development and are key members of the regulatory and science
community. PLRM PAC members will be asked to participate in this effort to provide feedback and
direction regarding data collection and data analysis strategies at critical milestones throughout this
study.
Description of Deliverables/ Products
The proposed research will consist of 4 distinct tasks. Each task will include feedback between data
obtained and PLRM pollutant load estimates in order to improve, test, and validate PLRM. The final
deliverables will be a SNPLMA Monitoring Plan, a database of monitoring data, a technical report, the
recommended PLRM refinements, and a detailed statistical and technical analysis of the information
and knowledge gained to directly improve PLRM estimates.
Task 1: SNPLMA Monitoring Plan
A detailed Monitoring Plan is currently under development for the initial USACE (2008) monitoring effort
to (1) justify and prioritize data collection needs based on the PLRM framework, (2) summarize the data
collection approach, and (3) identify sites, sampling protocols, sampling frequency, sampling equipment,
analytical analyses, etc. At the onset of work to be performed under this proposal, and after one
winter of monitoring through the USACE effort, the monitoring plan will be augmented and revised to
specifically build upon existing data and lessons learned. The revised Monitoring Plan will be reviewed
by the PAC prior to finalization.
Task 2: Station Implementation and Maintenance
Per the detailed Monitoring Plan protocols developed in Task 1, monitoring stations will be fabricated,
installed and maintained throughout the study.
Task 3: Data Collection, Data Management and Data Analysis
Water quality sampling efforts will be conducted per the protocols outlined in the Final Monitoring
Plan. Shortly prior to targeted storm water runoff events on land use specific sites, the condition of the
subject land use will be consistently evaluated and documented using draft RAM tools developed by the
research team. All data will be QA/QC’d and entered into an MS access database5 for efficient storage
and simple extraction. This task will include the continual integration of field data results with PLRM
inputs, as well as the testing and validation of PLRM outputs. The populated database will be posted on
TIIMS at the completion of the research.
Task 4: Draft and Final Technical Report
A detailed technical analysis will be conducted following data collection. Data analysis will build upon
the initial USACE data collection and analysis to recommend refinements to the PLRM CRCs and
CECs database. The final report will include a summary of the methods and protocols, recommended
database refinements, and a detailed statistical and technical analysis of the information and
knowledge gained to directly improve PLRM estimates. The PAC will review and provide feedback on
a presentation and the draft technical report. Comments will be incorporated into the Final Technical
Report.
5
The aforementioned DRI-led Performance of BMPs database development is scheduled to be completed near the onset of this research
The research team will either directly populate the newly developed BMP database with the storm water quality data generated from this
effort and/or ensure the data is managed in a compatible database framework.
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Research Proposal; SNPLMA Round 9 Theme: 2A
page 8
Schedule of Milestones/Deliverables
Begin:
(time since contract
award)
End:
(time since
contract award)
Revise and update ACE Monitoring Plan.
0 months
2 months
Conduct and summarize PAC meeting.
0 months
3 months
Revise and finalize Final Monitoring Plan.
3 months
4 months
Instrument stations. (Ideally in Fall 2009)
4 months
6 months
Maintain stations over course of project.
4 months
24 months
Collect controlled experiment data.
4 months
24 months
Collect event-based sampling data. (Ideally through Spring
2011)
4 months
24 months
Manage data.
4 months
24 months
Test, validate and refine PLRM.
4 months
24 months
Analyze data.
4 months
24 months
Draft Technical Report and present to TAC. (Ideally by October
2011)
25 months
28 months
Present Draft Technical Report to PAC.
28 months
30 months
Produce Final Technical Report. (Ideally by January 2012)
30 months
32 months
Task
1
2
3
4
Quarterly progress reports
Invoicing
2NDNATURE, LLC
1 st of September, December, March and
June throughout project duration
Ongoing monthly
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
page 9
References
In Proposal Text
Bertand-Krajewski, J., Chebbo, G., and Saget, A. 1998. Distribution of pollutant
mass vs. volume in storm water discharges and the first flush phenomenon.
Water Resources, 32(8): 2341-2356.
USACE. 2008. Lake Tahoe Initial CRC and CEC Urban Stormwater Data Collection to Inform PLRM.
Contract awarded October 22, 2008.
1
References used to estimate PLRM CRC and CEC
2NDNATURE. 2006. Lake Tahoe BMP Monitoring Evaluation Process, Synthesis of existing research.
Prepared for: USFS Lake Tahoe Basin Management Unit. October 2006. ftp://2ndnatureinc.
com/2ndnature/Tahoe%20References/
2NDNATURE 2006 is a synthesis of monitoring and performance data from 25 Lake Tahoe BMP
performance evaluation studies conducted on several different land uses. The specific studies
included were:
• 2NDNATURE. 2006B. Detention Basin Treatment of Hydrocarbon Compounds in Urban
Storm water. Prepared for: South Tahoe Public Utility District. March 2006.
• DRI. 2004. Evaluation of Effectiveness of Three Types of Highway Alignment Best
Management Practices for Sediment and Nutrient Control. Prepared for USFS-LTBMU, Nevada
Division of State Lands and Nevada Department of Transportation. December 2004.
• DRI & TERC. 2005. Efficiency Assessment of Storm water Treatment Vaults in the Round Hill
General Improvement District. Prepared for: NTCD and Nevada Division of State Lands. April
2005.
• SH+G. 2003. Assessment of Seasonal Pollutant Loading and Removal Efficiency of
Detention Basins. Prepared for: TRPA and US Environmental Protection Agency. February
2003.
• TERC. 2005. Performance Assessment of the Coon Street Basin, Kings Beach, CA. Prepared
for: Placer County Department of Public Works. March 2005.
• USGS. 2006. Changes in Ground-Water Flow and Chemistry after Completion of Cattlemans
Detention Basin, South Lake Tahoe, California – November 2001 to November 2003.
Prepared for: EDCDOT, Tahoe Engineering Unit. January 2006.
2NDNATURE. 2007. Water Quality Evaluation of a Fertilized Turf Surface in the Lake Tahoe Basin
(2002-2006). Prepared for: Nevada Tahoe Conservation District, Draft Final Report April 20, 2007.
ftp://2ndnatureinc.com/2ndnature/Tahoe%20References/
2NDNATURE. 2008. Water Quality Performance Evaluation of Park Avenue Detention Basins; South
Lake Tahoe, CA. Prepared for City of South Lake Tahoe Engineering Division. Final Technical Report.
August 15, 2008.
CalTrans. 2001. Final Report, CalTrans Tahoe Basin storm water monitoring program, Monitoring
Season 2000-2001 CTSW-RT-01-038. August 2001. http://www.dot.ca.gov/hq/env/storm water/
special/newsetup/index.htm#tahoe
CalTrans. J2003. Tahoe Highway Runoff Characterization and Sand Trap Effectiveness Studies,
2000-03 Monitoring Report: CTSW-RT-03-054.36.02. June 2003. http://www.dot.ca.gov/hq/env/
storm water/special/newsetup/index.htm#tahoe
2NDNATURE, LLC
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
Research Proposal; SNPLMA Round 9 Theme: 2A
page 10
CalTrans. A2003. Storm water Monitoring and Data Management, 2002-2003 Annual Data Summary
Report. CTSW-RT-03-069.51.42. August 2003. http://www.dot.ca.gov/hq/env/storm water/special/
newsetup/index.htm#tahoe
CalTrans. 2005. Deicer Report for Fiscal Year 2004-2005, CalTrans District 3. October 2005.
CalTrans. 2006. Storm water Monitoring and Research Program, 2004-2005 Annual Data Summary
Report. CTSW-RT-06-167.02.02. February 2006.http://www.dot.ca.gov/hq/env/storm water/special/
newsetup/index.htm#tahoe
Gunter, MK, 2005. Characterization of nutrient and suspended sediment concentrations in storm water
runoff in the Lake Tahoe basin. MS Thesis, Univ. Nevada Reno.
LRWQCB. 2007a. Lake Tahoe TMDL Technical Report. Lahontan Regional Water Quality Control Board.
South Lake Tahoe, CA.
LRWQCB. 2007b. Lake Tahoe TMDL Pollutant Reduction Opportunity Report. Lahontan Regional Water
Quality Control Board. South Lake Tahoe, CA.
2NDNATURE, LLC
321 Frederick Street Santa Cruz California 95062 phone 831-426-9119 fax 831-421-9023 email info@2ndnaturellc.com
PLRM WATER QUALITY APPROACH TO URBAN ROADWAYS
FIGURE 1
Road abrasive
applications
Risk Factors:
High population
density
Implement
advanced
road abrasive
application
strategies
Urban Road
Risk
Fine grained
soil type
Increase
road shoulder
protection
Pollutant
recovery
actions
Primary
pollutant
sources
Pollutant Recovery Actions
Urban Road Condition
PLRM land use
modeling steps
Source control
actions
Risk factors
Key
Increase road
sweeping
effectiveness
Remove Pollutants from Surface
improves
effectiveness
of
Localized erosion;
i.e road cut
Increase
road shoulder
stabilization
Reduce Pollutant Input Risk
Source Control Actions:
Urban Road
Pollutant Potential
Road shoulder
erosion
Increase Pollutant Source Risk
High road slope
2NDNATURE Draft Product
October 16, 2008
High traffic
density
A simplified conceptual summary of the PLRM approach to estimating the likely road CRC’s for total and very fine sediment. The PRLM user defines the physiographic factors,
source control and pollutant recovery actions for the primary and secondary roadways within the project area. PLRM integrates these components in a stepwise manner to estimate
the likely urban road conditions. The continuum of road condition, from good to poor, is assumed to correlate to a specific CRC for each pollutant of concern. The associated CRC
decreases as the condition of the roadways increase. The proposed research will directly inform the quantitative relationship between these multitude of factors and the resulting
urban road condition and associated CRC.
Pollutant Reductions
_
+
Pollutant Sources
PLRM Urban Road Condition
as related to Total and Very Fine Sediment charactertistic runoff concentrations (CRCs)
PLRM Water Quality Approach to SWT
Untreated Flow
Bypass
Qin > Qmax
Inflow
Surface Area
Qin < Qmax
Optional Diversion
Flow Rate
Depth
Bypass Flow
Water Quality
Volume
Treated Flow
Infiltration Rate
Drain Time or
Stage Discharge Curve
A simplified conceptual summary of the PLRM approach to compute the performance of a
detention basin, one type of SWT:
Step 1 – Long-term simulations are employed to determine continuous catchment hydrology
and calculate the fraction of total runoff volume that passes through an SWT at or below a
specified design capacity (capture ratio).
Step 2 - The captured volume is assumed to be treated to the CEC for the SWT specified.
Step 3 - The bypassed volume is assumed to have no reduction from the influent quality.
Step 4 - Loads are computed as the product of flow volume and concentration for the treated
portion and the bypassed portion, and the pollutant load at the outlet of the SWT is the sum of
these two loads.
The proposed research will decrease the significant data gaps concerning the fate and transport
of very fine sediment in typical Lake Tahoe SWTs, thereby improving the PLRM estimates of
characteristic effluent concentrations that are assumed to vary by SWT type and key design
characteristics.
CONCEPTUAL PLRM WATER QUALITY APPROACH TO SWT
FIGURE 2