DEVELOPMENT OF A BMP PERFORMANCE ASSESSMENT AND DATA
ANALYSIS SYSTEM FOR THE TAHOE INTEGRATED INFORMATION
MANAGEMENT SYSTEM (TIIMS)
JANUARY 26 2007
Proposal to Conduct Research in Support of the
Lake Tahoe Environmental Improvement Program
Prepared for:
Lake Tahoe Basin Research
USDA Forest Service
Pacific Southwest Research Station
Prepared by:
Desert Research Institute, Geosyntec Consultants, UC Davis, 2NDNATURE, & northwest hydraulic consultants
northwest hydraulic consultants inc.
Development of a BMP Performance Assessment
and Data Analysis System for the Tahoe Integrated
Information Management System (TIIMS)
Proposal to Conduct Research in Support of the Lake
Tahoe Environmental Improvement Program
Prepared for:
Lake Tahoe Basin Research
USDA Forest Service
Pacific Southwest Research Station
Prepared by:
Desert Research Institute
Geosyntec Consultants
2NDNATURE
northwest hydraulic consultants
January 26, 2007
Table of Contents
I.
Project Team and Contact Information.................................................................................. 1
II. Justification Statement ........................................................................................................... 2
III. Background/Problem Statement ............................................................................................ 2
IV. Proposed Goals, Objectives and Hypotheses......................................................................... 3
V. Approach, Methodology, and Geographic Location of Research.......................................... 4
VI. Deliverables/Products .......................................................................................................... 10
VII. Schedule of Events/Reporting and Deliverables.................................................................. 10
VIII. Budget .................................................................................................................................. 11
IX. Relevant Projects and Investigator Resumes ....................................................................... 11
i
Lake Tahoe EIP Research Proposal
I. Project Team and Contact Information
Principal Investigators:
Alan Heyvaert, Desert Research Institute
2215 Raggio Parkway, Reno, NV 89512
phone: 775-673-7322, fax: 775-673-7363
email: alan.heyvaert@dri.edu
Eric Strecker and Marc Leisenring, Geosyntec Consultants
55 SW Yamhill St., Suite 200, Portland, OR 97204
phone: 503-222-9518, fax: 503-242-1416
email: estrecker@geosyntec.com and mleisenring@geosyntec.com
Nicole Beck, 2NDNATURE
321 Frederick St. Santa Cruz, CA 95062
phone: 831-426-9119, fax:831-421-9023
email: nbeck@2ndnatureinc.com
Ed Wallace and Brent Wolfe, northwest hydraulic consultants
3950 Industrial Blvd., Suite 100c, West Sacramento, CA 95691
phone: 916-371-7400, fax: 916-371-7475
email: ewallace@nhc-sac.com and bwolfe@nhc-sac.com
Charles Goldman, University of California-Davis
One Shields Avenue, Davis, CA 95616
phone: 530-752-1557, fax: 530-752-3350
email: crgoldman@ucdavis.edu
Grants Contact Person:
Yvonne Rumbaugh, Desert Research Institute
2215 Raggio Parkway, Reno, NV 89512
phone: 775-673-7366, fax: 775-673-7363
email: yvonne.rumbaugh@dri.edu
Addressed Theme and Sub-Theme
Theme 5: Best Management Practices (BMP) Implementation and Effectiveness
Sub-Theme B: Develop models and design a monitoring program to assess BMP effectiveness
in meeting regulatory requirements for pollutant reduction.
-1-
Lake Tahoe EIP Research Proposal
II. Justification Statement
Lake Tahoe is designated an Outstanding National Resource Water (ONRW) under the USEPA
Water Quality Standards Program and the Clean Water Act. It is also listed as a CWA 303(d)
impaired waterbody by the Nevada Division of Environmental Protection and the California
State Water Resources Control Board. This has triggered development of the Total Maximum
Daily Load (TMDL) pollution control plan, which is currently underway, and the Tahoe
Environmental Improvement Program (EIP).
The Lake Tahoe Watershed Assessment stated that “restoration of existing erosion problems”
and “treatment of urban surface flow” were two of the “most appropriate courses of action” to
stop the decline in Lake Tahoe’s clarity (USDA Forest Service et. al, 2000, p. 306). A basinwide implementation of Best Management Practices (BMPs) on new development and the
retrofitting of existing development with BMPs has been widely recognized as the most effective
way to reach these goals. To date, however, BMP performance data and design information have
generally not been collected using a standard set of monitoring and reporting protocols, so it is
difficult to develop an in-depth understanding of BMP selection and design effects on resulting
pollutant loadings. The Tahoe TMDL program will require an accounting of load reductions
provided by EIP and BMP implementations. Both programs would benefit substantially from
application of appropriate monitoring and reporting metrics, and protocols for BMP and erosion
control project evaluations, as well as a database designed to store collected information for
evaluation purposes.
Given the variability in monitoring and reporting of BMP performance, it has been very difficult
if not impossible to develop non-residential BMP selection and design guidance or tools that
optimize load reductions. Consistent BMP performance data is critical not only for helping to
provide information for setting and initially implementing TMDLs, but especially in evaluating
the results over time to allow improvements in load allocations and reduction targets as TMDLs
are progressively implemented over the next 20 years.
III. Background/Problem Statement
The Tahoe Regional Planning Agency (TRPA) has initiated a program to develop Phase II
portions of the Tahoe Integrated Information Management System (TIIMS) TMDL EIP/BMP
toolkit. Ultimately, the TIIMS database is intended to house load reduction data in a central
location to assure comprehensive tracking of the Tahoe Basin’s water quality data, and to
provide watershed managers with the quality and quantity of data needed for adopting
appropriate TMDL targets. Toward these goals, the TRPA would benefit substantially from the
implementation of a non-residential BMP database, integrated as part of TIIMS for assessing
performance and for tracking maintenance activities. This database should be dedicated to the
higher resolution monitoring data typical of non-residential BMP performance assessment, and
should incorporate a standardized set of protocols for monitoring, reporting and data evaluations.
Without such a system in place, any quantitative integration of existing stormwater quality and
BMP effectiveness data is extremely difficult and very time consuming.
-2-
Lake Tahoe EIP Research Proposal
The main objective of this proposal is to develop the tools needed for consistent and statistically
comparable BMP monitoring and assessment. This will build upon preliminary work already in
progress for the Tahoe Basin Stormwater Monitoring Network, funded through an EPA grant
(X7-969471010) to the University of California Tahoe Environmental Research Center (TERC)
and the Desert Research Institute (DRI). As part of that program, the project team has assembled
substantial data on stormwater runoff characteristics at Tahoe and has established preliminary
field collection procedures, data management and reporting formats. This proposal will extend
that effort to develop a similar set of tools adapted for high resolution BMP performance
monitoring and reporting. Furthermore, this proposal will support the integration of those tools
directly into the TIIMS EIP/BMP toolkit. This will contribute to the utility of TIIMS as a TMDL
load reduction tracking system by providing effectiveness information on individual BMPs as
well as load reduction information on a watershed scale. The tools developed here shall help
ensure the consistency and quality of results, such that data generated by various agencies,
institutions, jurisdictions and consultants will be suitable for direct uploading into the basin-wide
TIIMS database.
By standardizing monitoring methods and reporting formats, the data from various sources can
be combined in TIIMS to provide information on the relative effectiveness and performance
trends for different types of non-residential BMPs. Periodic statistical analyses will then extract
information from the total set of monitoring programs, which provides more information than
would be obtained from individual BMP performance assessments alone. This represents
economies of scale possibilities as data are collected over time from multiple projects in the
Tahoe Basin, which could significantly reduce long-term monitoring costs for BMP cost-benefit
evaluations, and for maintenance and performance tracking purposes.
The project proponents have extensive experience with all aspects of BMP performance
evaluation and reporting, from national programs to regional and local projects (see Section IX
for details).
IV. Proposed Goals, Objectives and Hypotheses
Goals:
1. Develop standardized protocols for monitoring, reporting, and evaluating BMP
performance in Lake Tahoe.
2. Create a functional database populated with Lake Tahoe specific hydrologic and water
quality data to inform BMP performance predictions, BMP design, and BMP
maintenance approaches.
Objectives:
1. Develop BMP performance monitoring and data reporting protocols for the Tahoe Basin.
2. Develop a quantitatively functional non-residential BMP maintenance and monitoring
database.
-3-
Lake Tahoe EIP Research Proposal
Hypotheses:
1. Water quality performance of various BMP types is influenced by hydraulic loading,
influent concentrations, siting and design factors, and maintenance practices.
2. The unique climate, geology, vegetation, environmental management practices, and
desired water quality in Lake Tahoe result in conditions and treatment processes that are
unique to Lake Tahoe.
V. Approach, Methodology, and Geographic Location of Research
Primary Tasks:
1. Identify Planning, Management and Technical Needs of BMP Database.
2. Identify BMP Performance Data Gaps and Monitoring Needs
3. Establish BMP Monitoring and Data Reporting Protocols and Develop Guidance
Document
4. Develop Lake Tahoe BMP Database
5. Populate Database with Existing BMP Performance Data and Prepare Initial Statistical
Summary Report
6. Work with TRPA to Implement Tahoe BMP Database on the TIIMS
The following paragraphs summarize the activities under each of the five tasks.
TASK 1. IDENTIFY PLANNING, MANAGEMENT AND TECHNICAL NEEDS OF BMP
DATABASE.
1.1
Develop goals and identify uses of a non-residential BMP database
The project team would collaborate with local agency personnel to refine and document the
purpose, needs and expectations of the database to ensure it would be a functional tool for
researchers and resource managers. It is expected that the database would be used to manage
and summarize high-resolution BMP data that could be applied to bigger questions regarding
Basin-wide water quality improvements.
1.2
Review TIIMS database and discuss approach with TIIMS Technical Team
An early dialogue with the TIIMS Technical Team regarding the existing structure of the TIIMS
database would occur to ensure consistency and coordination with existing efforts. The overall
approach would be discussed with key individuals and comments and concerns would be
documented.
-4-
Lake Tahoe EIP Research Proposal
1.3
Develop brief memo outlining the long-term goals and utility of the database
Based on the outcome of the correspondence with local agencies, researchers, and key TRPA
staff, a brief memo would be developed that summarizes the purpose, needs, and expectations of
the non-residential BMP database, as well as the overall implementation strategy and any
identified challenges.
TASK 2. IDENTIFY BMP PERFORMANCE DATA GAPS AND MONITORING NEEDS
2.1
Identify and compile Tahoe-specific monitoring data and identify data needs for
ongoing pollutant load reduction estimation efforts
The project team has an excellent understanding of existing Tahoe BMP monitoring data. In
addition, the project team is working on development of methods for quantitative estimates of
pollutant load reductions associated with BMP implementation (PLRE-STS methodology) and is
familiar with basin-wide modeling activities (TMDL Watershed Model and Lake Clarity Model).
Therefore, the team is well aware of key parameters needed to support existing modeling efforts.
In previous studies, team members have reviewed sources of available Lake Tahoe BMP
performance data. This experience would be used as the basis for updating and compiling
available information and assessing BMP performance data gaps from the perspective of EIP
project evaluation.
This approach would identify not only the types of non-residential BMPs for which data is sparse
or absent, but the monitoring parameters needed to make reasonable BMP performance estimates
as well as information that would be helpful for improving BMP design. The project team would
solicit input from researchers, monitoring programs, and water quality specialists in the Basin to
ensure the data gap identification covers a broad range of potential applications and modeling
tools.
A list of data gaps for specific non-residential BMP types would be compiled and ranked in
priority according to relevance to project evaluations, BMP selection, and protection of receiving
waters.
2.2
Research existing BMP performance monitoring protocols.
Local protocols developed specifically for monitoring the performance of stormwater BMPs are
generally limited to inter-agency guidelines containing few, if any, standardized approaches for
conducting performance monitoring or compiling adequate information for meaningful
predictive analyses. At the national scale, the most complete BMP monitoring protocols are
those developed for the WERF/ASCE/EPA International BMP database
(www.bmpdatabase.org). These protocols include specific monitoring and data reporting
requirements with the ultimate goal of producing a universally accessible and densely populated
database of BMP performance study information. The international scale of the database has
resulted in protocols that could specifically support all of the data gaps and monitoring needs of
the Tahoe Basin. Local experience with monitoring and data reporting has resulted in
monitoring guidance and protocols that may also be used to address data gaps and needs in the
Basin. Therefore in addition to reviewing the protocols for the WERF/ASCE/EPA BMP
-5-
Lake Tahoe EIP Research Proposal
Database, the team will also review methodologies, approaches and reporting protocols used for
previous Tahoe BMP evaluation studies that have successfully quantified BMP performance.
2.3
Complete data gaps and monitoring needs memo.
A technical memo summarizing the data gaps and monitoring needs in support of existing load
reduction estimation efforts and existing protocols will be developed.
TASK 3. ESTABLISH BMP MONITORING AND DATA REPORTING PROTOCOLS
AND DEVELOP GUIDANCE DOCUMENT
3.1
Establish target water quality parameters, analytical methods, reporting limits, and
QA/QC requirements.
One of the goals of the Lake Tahoe Interagency Monitoring Program (LTIMP) is to develop
monitoring strategies in support of regulatory, management, planning and research activities in
the Tahoe Basin. To leverage off the history and experience of this program, key LTIMP
personnel, as well as the TIIMS Technical Team, the LRWQCB, and the NDEP, would be
consulted. Existing monitoring plans and protocols would be reviewed to evaluate existing data
collection, QA/QC, and reporting requirements. This information would be evaluated for
compatibility with specific BMP monitoring activities. A standard minimum list of analytical
parameters applicable to water quality performance evaluations would then be developed, as well
as an expanded optional list of desirable analytical parameters.
3.2
Identify and categorize non-residential BMP types.
Based on the prioritized data gaps for specific non-residential BMP types identified in Task 2,
BMPs to be included in the monitoring protocols would be selected. The selected BMP types
would then be categorized based on factors that influence sample collection and flow monitoring
techniques, such as inflow/outflow characteristics and typical scale of implementation.
3.3
Evaluate existing fields and formats of existing databases.
The WERF/ASCE/EPA BMP Database was developed to accept a wide array of BMP design
and performance information with the intent of being both comprehensive and flexible. This
intent has necessarily resulted in a database structure containing a large quantity of data fields
and tables, some of which are required for all BMP performance studies, but many that are not
required or applicable to certain BMP types. The purpose of this subtask would be to summarize
the required and optional data fields and formats in the WERF/ASCE/EPA International BMP
Database and the existing TIIMS residential BMP database with respect to the BMP performance
data gaps identified in Task 2. This effort also would include the incorporation of key
parameters, protocols and reporting strategies of successful Tahoe Basin BMP evaluations.
3.4
Develop minimum monitoring and reporting requirements.
Desirable parameters to monitor and report for any particular BMP study largely depend on the
static and state variables that affect the functionality of the BMP system. For example, static
variables that can directly affect BMP system function include: BMP design (e.g., volume, outlet
-6-
Lake Tahoe EIP Research Proposal
design, etc.), geographical location, watershed size, imperviousness, soils, etc. State variables
that directly affect BMP function may include: rainfall intensity, flow rate, season, maintenance
condition, etc. This subtask would identify the static and state variables that are likely to affect
the functionality of each BMP type. A list of minimum monitoring and reporting requirements
would be developed and some monitoring techniques that could be used to collect this
information would be identified.
3.5
Develop general and BMP-specific data entry forms.
Data entry forms are needed to assist in obtaining complete and consistent information. They
also assist in the development of the database structure as they clearly describe and organize the
desired information to be collected. Target Tahoe agencies with relevant BMP monitoring
programs would be contacted and current data reporting requirements and formats would be
obtained. These requirements and formats would then be reviewed to identify common
characteristics and inconsistencies, as well as identify additional data fields not previously
considered.
Both general and BMP-specific data entry forms are needed. For example, precipitation
characteristics and watershed factors (e.g., drainage area, imperviousness, average slope, etc.),
are useful information to include with all BMP performance studies, while critical design factors
(e.g., BMP volume, length-to-width ratio, vegetative cover, etc.) will depend on the BMP type.
Therefore, for each BMP type, the minimum data reporting requirements would be established
and integrated into BMP-specific data entry forms. The WERF/ASCE/EPA BMP Database team
is currently building spreadsheet data entry forms that should be adaptable for this effort.
3.6
Develop a template BMP inspection protocol and maintenance reporting format
For a selected BMP type in the database (e.g., extended detention basins) the project team will
identify typical maintenance activities and develop recommended inspection parameters that can
support BMP performance estimates. The project team will produce preliminary maintenance
inspection forms for the selected BMP type, and distribute for comment to agencies and other
entities responsible for BMPs.
In addition to tracking and better defining the maintenance activities required to sustain
performance, maintenance inspections have potential to support the BMP monitoring database
and its use in performance evaluations. Although maintenance activities do not typically involve
sampling, some samples may be collected in association with maintenance or occasional
monitoring. Although these grab samples are difficult to interpret individually, there is the
potential for a large body of samples, if collected using a consistent protocol, to contribute to the
overall understanding of BMP performance (by supplementing more detailed, rigorous, and
continuous monitoring programs that meet the protocols developed in task 3.4). Therefore, a
second set of protocols will be developed for agencies and jurisdictions so that samples
associated with normal maintenance activities or occasional monitoring can contribute to and
supplement the database. The project team will develop a simple template protocol for the
selected BMP and include database elements for storing this type of information and tracking
BMP maintenance actions.
-7-
Lake Tahoe EIP Research Proposal
3.7
Develop BMP monitoring guidance document.
Using the established BMP monitoring protocols, a document that provides concise monitoring
and reporting guidance for the selected BMP types would be developed. The intent of the
guidance would be to provide simple instructions on how to meet the established BMP
monitoring protocols. Reference to the more detailed BMP monitoring guidance document
produced for the WERF/ASCE/EPA International BMP Database1 as well as other guidance
from such agencies as the Federal Highway Administration (FHWA) would be provided for
developing general BMP monitoring plans and programs.
TASK 4. DEVELOP LAKE TAHOE NON-RESIDENTIAL BMP DATABASE
4.1
Review the WERF/ASCE/EPA International BMP Database schema.
With reference to the Tahoe-specific monitoring protocols developed in Task 3, the feasibility of
utilizing the relational structure of the WERF/ASCE/EPA BMP Database for Tahoe BMPs
would be evaluated and compatible components would be extracted and summarized.
4.2
Review the current online Tahoe BMP database on TIIMS.
The Tahoe Integrated Information Management System (TIIMS) is a website being developed by
TRPA and its partners to house and disseminate information about Lake Tahoe Basin planning
and restoration efforts. This subtask would include contacting the TIIMS Technical Team and
reviewing in detail their underlying database and web interface software and discussing initial
database development steps.
4.3
Develop database tables and schema.
Based on the review of the WERF/ASCE/EPA Database and the TIIMS database, a
comprehensive database development strategy would be developed. This would include
selecting the underlying database and online interface software. Using the protocols developed
in Task 3, all required and optional data fields and formats for each BMP type would be
tabulated. Data fields would be grouped based on the type of information provided. The final
schema for the database would then be developed. A design and specification document to be
used in the implementation and maintenance of the database would be started and updated as the
project progresses.
4.4
Develop data entry and reporting interface.
Once the structure and platform for the database are selected and documented, the user interface
would be designed and documented. Data consistency checking and data preservation protocols
would also be established to streamline automated QA\QC and system data backup policies. The
database design and specification document would be updated with QA\QC and data
preservation protocols and data entry and data reporting specifications.
1
GeoSyntec Consultants, Urban Drainage and Flood Control District, and Urban Water Resources Research Council
(UWRRC) of ASCE (2002). Urban Stormwater BMP Performance Monitoring - A Guidance Manual for Meeting
the National Stormwater BMP Database Requirements. EPA-821-B-02-001.
-8-
Lake Tahoe EIP Research Proposal
TASK 5. POPULATE DATABASE WITH EXISTING BMP PERFORMANCE DATA
AND PREPARE INITIAL STATISTICAL SUMMARY REPORT
5.1
Review and evaluate existing BMP monitoring data.
To build upon preliminary efforts to synthesize BMP performance data conducted by
2NDNATUREError! Bookmark not defined., existing BMP monitoring data would be evaluated. Local
agencies and researchers conducting BMP assessments in the Tahoe Basins would be contacted
and summary reports would be obtained. BMP data sets that meet or exceed the minimum data
requirements would be identified. Studies with data sets that nearly meet the minimum data
requirements would be evaluated to determine the effort involved to obtain the missing or
incomplete information. If feasible within budget limitations, the missing data would be
obtained.
5.2
Populate database using database entry forms.
Existing data that meets the minimum protocols would be entered into the database. Automated
means of data entry would be evaluated and used wherever possible. Any issues with the data
entry / reporting interface would be corrected and future usability improvements would be
recommended.
5.3
Prepare initial statistical summary report.
The initial statistical summary would be largely based on the number and type of BMPs added to
the database and the quality and quantity of the initial data set. Nonetheless a statistical analysis
plan would be developed that would include evaluating data characteristics and conducting
appropriate hypothesis tests. Descriptive statistics of effluent concentrations for each BMP type
would be computed and, to the extent possible, the effects of influent concentrations, design
parameters, and/or precipitation characteristics would be investigated. The initial statistical
summary report would identify any additional data that may be useful for evaluating BMP
performance and provide a reevaluation of the optional versus required data sets. The
WERF/ASCE/EPA BMP database data evaluation reports will provide a model for this effort.
TASK 6. WORK WITH TRPA TO IMPLEMENT THE BMP DATABASE ON THE
TIIMS WEBSITE
6.1
Introduce monitoring protocols and demonstrate non-residential BMP database to
TRPA, LRWCQB, and NDEP.
A meeting with TRPA, LRWCQB, and NDEP would be scheduled to discuss the BMP
monitoring protocols and demonstrate the functionality of the database. The initial statistical
summary would be presented along with some basic database queries.
6.2
Meet with TIIMS Technical Team to discuss implementation strategies.
A final meeting with the TIIMS Technical Team would be scheduled to discuss implementation
strategies, administrator responsibilities, user accessibility options, and long-term database
maintenance. It may be decided that a phased implementation approach may be necessary
-9-
Lake Tahoe EIP Research Proposal
depending on specific TRPA network system constraints and the availability of TRPA staff to
implement the database.
6.3
Develop memo describing implementation strategy.
A final technical memo would be developed describing a strategy for integrating the BMP
database on the TIIMS website, as well as making the BMP monitoring protocol guidance
document available on the web. This final memo as well as data entry forms and data reporting
templates would be provided to the TIIMS Technical Team to assist in the implementation.
VI. Deliverables/Products
A list of deliverables is provided below:
1. Technical memo outlining the technical and management need for and utility of a Tahoe
BMP database.
2. Technical memo summarizing and prioritizing BMP performance data gaps and needs in
the Tahoe Basin, including a list of monitoring activities that could potentially assist in
filling those data gaps.
3. BMP Performance Monitoring and Reporting Protocols Guidance document.
4. A concise, initial BMP database statistical summary report.
5. Technical memo with implementation strategy outlined. The final draft would be
submitted to the TRPA TIIMS Technical Team for consideration.
VII.
Schedule of Events/Reporting and Deliverables
- 10 -
Lake Tahoe EIP Research Proposal
Relevant Projects and Publications:
International Database on Urban Stormwater BMP Design and Performance
U.S. EPA and American Society of Civil Engineers
Geosyntec is one of the two principal investigators that is participating in a team with Wright
Water Engineers, and other members of the American Society of Civil Engineers (ASCE) Urban
Water Resources Research Council (UWRRC) on an ASCE project to develop a scientifically
based approach and management tool to evaluate the effectiveness of urban stormwater runoff
BMPs worldwide (www.bmpdatabase.org).
The goal of the project is to promote technical design improvements for BMPs and to better
match their selection and design to local stormwater problems. The effort has included
development of a set of monitoring and reporting protocols for use by researchers in performing
BMP monitoring that will make individual BMP studies much more useful for design evaluation,
when comparing multiple studies. Additional tasks include gathering currently available data on
BMP performance, including attempting to gather as many of the protocol data as possible, and
developing an initial assessment of BMP design and performance.
Geosyntec’s role is to perform the technical evaluation of the data currently in the database to
investigate effects of design on BMP effectiveness and to develop a comprehensive guidance
document on how to conduct BMP effectiveness studies such that the monitoring and reporting
protocols are met. In addition, Geosyntec is providing technical support as requested to database
users. The knowledge gained from this work is directly beneficial to clients who are looking for
proven stormwater technologies to apply in their projects.
Best Management Practices Implementation Feasibility Study
Lake Tahoe Research Group UC Davis and Lahontan Regional Water Quality Control Board
TMDLs (Total Maximum Daily Loads- Pollutant loading limits) are in the process of being
developed for Lake Tahoe watershed to address concerns about diminishing clarity of the Lake.
The overall effort includes development of source characterization and loading models, assessing
and identifying the assimilative capacity of the Lake for selected pollutants, and assessing the
potential effectiveness of best management practices to address stormwater and dry weather
runoff flows to the Lake. Finally, with this information and a public process, TMDLs will be set
with an implementation schedule.
Geosyntec was contracted to assist with the (Best Management Practice) BMP feasibility portion
of the project. The purpose of this BMP Implementation Feasibility Study was to evaluate the
cost-effectiveness and other attributes (e.g., secondary benefits and impacts) of project level and
basin-wide BMP implementation. In order to accomplish this objective, the Feasibility Study
identified the effectiveness and costs of a variety of currently implemented BMPs in the Tahoe
Basin (including designs and sizing), as well potentially effective new or innovative
technologies. Our work focused on specifically addressing Lake Tahoe issues of phosphorus and
fine particulates in runoff. The work focused on specifically addressing Lake Tahoe issues of
phosphorus and fine particulates in runoff. A continuous simulation model was used to evaluate
treatment performance as a function BMP size and hydraulic retention time. This information
- 13 -
Lake Tahoe EIP Research Proposal
was incorporated into a GIS-based watershed model to estimate the annual loading of pollutants
into the lake on a basin-wide scale as well as the potential effectiveness of various BMP
implementation strategies. We also provided overall input into the modeling approaches as well
as monitoring efforts in the Tahoe Basin.
Methodology to Estimate Pollutant Load Reductions
US Army Corps of Engineers and Lahontan Regional Water Quality Control Board
GeoSyntec Consultants and Northwest Hydraulic Consultants (nhc) jointly developed new
methodologies that can be used to estimate or quantify pollutant load reductions associated with
water quality improvement projects in the Lake Tahoe Basin. This completed work will directly
support Phase II of the TMDL program, which will involve alternatives and allocations for load
reductions. The primary tasks associated with this work included: 1) investigation of local and
regional water quality improvement practices and policies; 2) summarization of existing
information and water quality improvement programs at a national level; and, 3) development of
a load reduction methodology.
The developed methodology is a substantial step forward towards the estimation of pollutant
load reductions from the implementation of water quality improvement projects in the Lake
Tahoe Basin. The methodology is based in physical processes for hydrology and some aspects
of pollutant load reduction (e.g., sedimentation) while incorporating empirical data on pollutant
loads by land use and BMP performance. The methodology includes continuous hydrologic
simulations and time series computations for expected water quality performance focused on
pollutant load generation and reduction associated with surface runoff from drainage basins
affected by urban development.
The initial prototype spreadsheet tool characterizes the effectiveness of three primary urban
storm water project components: (1) hydrology, including the effects of hydrologic source
controls in reducing runoff; (2) pollutant load generation, including the effects of pollutant
source controls; and (3) storm water treatment, focusing on centralized BMPs that remove
pollutant loads from collected runoff. Using computational procedures developed in the
spreadsheet tool, the overall pollutant load reduction associated with water quality improvements
is the net result of hydrologic source controls, pollutant source controls, and centralized storm
water treatment.
Wetland Treatment System Performance Assessment
Heyvaert, A.C., J.E. Reuter, and C.R. Goldman. 2006. Subalpine, cold climate, stormwater
treatment with a constructed surface flow wetland. Journal of the American Water Resources
Association (JAWRA) 42(1):45-54.
A variety of structural best management practices (BMPs) are commonly used to mitigate the
increased hydraulic, nutrient and sediment loads from stormwater runoff in urbanized areas.
Wetlands have been demonstrated as particularly effective in many temperate areas of the
country, due to a mosaic of natural biological processes that exist within these systems. Most
precipitation in the Tahoe Basin occurs with winter storms, however, when wetland vegetation is
dormant. This study investigates the effectiveness of constructed wetland systems at Lake Tahoe
in removing nutrients and sediments throughout the year. Monitoring data from the Tahoe City
Wetland Treatment System indicate improvement of 50% or greater in effluent concentrations of
dissolved phosphorus, nitrate, orthophosphorus, and total suspended solids. On average, during
- 14 -
Lake Tahoe EIP Research Proposal
WY2003 for example, event mean concentrations of total phosphorus were reduced from a
median 279 µg/L at the inflow to 94 µg/L at the outflow. Event mean concentrations of total
nitrogen were reduced from a median 1599 µg/L at the inflow to 810 µg/L at the outflow. This
project will continue to assess long-term performance of wetland systems, and will investigate
management options for enhancing performance under various hydraulic conditions.
Chemically Enhanced Stormwater Treatment Systems
Bachand P., A. Heyvaert, J. Reuter, R. Fujii. 2007. Chemical Treatment Methods Pilot (CTMP)
for Treatment of for Urban Runoff. Draft Final Report for the City of South Lake Tahoe.
This is a collaborative effort between UCD, DRI, the Office of Water Programs at CSUS,
Caltrans and Bachand & Associates to investigate the application of chemical media and
coagulants for treatment of stormwater runoff from urban areas and highways in the Tahoe
Basin. There are natural limits to the amount of treatment that traditional management practices
can achieve. These efficiencies may not be adequate for the level of treatment required to restore
Lake Tahoe’s clarity. In which case, alternative practices would be required in those locations
where pollutants concentrations are very high or where there is limited opportunity for the
installation of large treatment areas like detention basins and wetlands. These chemical treatment
studies are looking at the various types of natural and synthetic treatment chemicals available,
their potential effectiveness under different temperature and water quality conditions, the cost
and maintenance requirements associated with chemical treatment, and any potential
environmental or toxicological effects from chemical treatment systems.
Lake Tahoe Basin Stormwater Monitoring Network
Contact: Alan Heyvaert, Ph.D., (775) 673-7322, alan.heyvaert@dri.edu
Tributary streams to Lake Tahoe have been monitored and studied for decades, but relatively
little was known about the quantities and the characteristics of runoff from intervening zones
between the watersheds. Many of these intervening areas that drain directly into the lake are
highly urbanized, and contribute a significant amount of total nutrient and fine sediment lake
loadings. Preliminary data, for example, indicate that more than 25% of total phosphorus loading
into Lake Tahoe is derived from intervening areas between tributary streams. The objective of
this collaborative project between UCD and DRI is to establish a network of monitoring sites
that collect runoff data from various land use areas, and to statistically describe the
characteristics of runoff from different land use and land cover types.
Paleolimnological Reconstruction of Lake and Watershed History
Heyvaert, A.C., J.E. Reuter, C.R. Goldman, and D.N. Edgington. 2000. Environmental history of
the Tahoe Basin as reconstructed from lake sediment cores. Geological Society of America
Proceedings, Vol. 32(7).
While our monitoring record from Lake Tahoe is one of the longest environmental monitoring
datasets in the world, but it does not extend to predisturbance conditions. There is much to be
learned about lake response to watershed disturbance by looking at the historical record
contained in lake sediments. These sediments are laid down year by year and accumulate over
time. Analysis of sediment cores, like tree rings, allows us to look at a historical record of prior
conditions, disturbances and response patterns. We now know, for example, that lake
sedimentation during clearcut logging of the Comstock era, in the late 1800s, was about twice
the current sedimentation rate. Algal diatom productivity was also about twice the current level.
- 15 -
Lake Tahoe EIP Research Proposal
Yet sedimentation rates and algal productivity returned nearly to pre-Comstock baseline levels
after logging ended and the watershed recovered, before urbanization. This indicates that lake
response to watershed recovery is rapid, at a decadal scale, compared to the lake’s hydraulic
retention of 600 years. Therefore, evidence of Lake response to appropriate watershed
management would also be expected at the decadal scale, from 10-30 years. Much work
continues on this project, including studies on effects from flood and drought cycles, from
atmospheric and watershed pollution, and from climate variability.
Use of Periphyton Biofilms for Stormwater Treatment
Patterson, S., A. Heyvaert, C. Strasenburgh. 2007. Pilot Water Quality Treatment System for the
Lake Tahoe Basin: Phosphorus and Fine Particle Removal by Cultured Periphyton. Draft Final
Report for the Nevada Tahoe Conservation District.
This is a collaborative effort between DRI, UCD, and Biological x Design to investigate the use
of cultured biofilms for enhanced removal of nutrients and fine sediment particles from
stormwater. While traditional stormwater treatment methods like detention basins can be
effective for removal of coarse sediments and particulate nutrients, they tend to be less effective
for the removal of dissolved nutrients and very fine-grained particles. Chemical treatment
methods may enhance this process, but their application can be expensive and may have
ancillary deleterious effects. We are looking at the other side of the treatment spectrum and
investigating the functional processes involved in use of natural and cultured biofilms for
improving water quality prior to discharge to the lake. Periphyton samples collected from the
near-shore zone of Lake Tahoe and from Tahoe streams have been grown and tested in large
mesocosm tanks for efficiency of stormwater treatment. The results are encouraging, and suggest
that for some applications a combination of these approaches may provide the most costeffective improvements in stormwater treatment. Work on this project continues as we
investigate the variety of processes involved in natural treatment systems and the utility of
periphyton biofilms for capturing fine-grain particles and removing nutrients.
Detention Basin Performance Assessment
Heyvaert, A., and A. Parra. 2005. Performance Assessment of the Coon Street Detention Basin,
Kings Beach CA. Final Report for the Placer County Department of Public Works and the
California Tahoe Conservancy.
Detention basins are one of the more commonly installed best management practices (BMP) in
the Tahoe Basin. However, the effectiveness of these BMPs had not been determined for the
typical series of annual storm events at Lake Tahoe, where most of the precipitation occurs with
large frontal winter storms and subsequent snowmelt. This study looked at the relative
performance of a typical detention basin in Lake Tahoe over the course of two water years, in
terms of hydraulic retention characteristics, nutrient removal and sediment deposition. Analytic
data from event mean concentrations (EMC) were compiled with the corresponding event
volumes and then event inflow and outflow loads were estimated. The medians for analyte
EMCs were relatively similar between water years, especially the influent concentrations. Only
nitrate-N, suspended solids and turbidity showed much difference in their median EMC
concentrations between water years. In combination with the EMC data, annual loading
estimates indicated that the basin is achieving effluent reductions somewhere in the range of 86–
95% removal for suspended solids, 71–88% removal for total phosphorus, 44–75% removal for
orthophosphate-P, 46–73% removal for nitrate-N, and 33–61% removal for ammonium-N.
- 16 -
Lake Tahoe EIP Research Proposal
Annual basin inflow volumes during this period were estimated to be 8–27% greater than
outflow volumes, with the difference presumably lost to infiltration and evapotranspiration.
Evaluation of Treatment Vaults for Improving Residential Stormwater Runoff
Heyvaert, A., R. Jacobson, T. Mihevc. 2005. Efficiency Assessment of Stormwater Treatment
Vaults in the Round Hill General Improvement District. Final Report for the Nevada Tahoe
Conservation District and the Nevada Division of State Lands.
Stormwater treatment vaults are often used in drainages where there is insufficient space
available for the installation of open detention basins or wetlands. Information on the
effectiveness of vault BMPs for treating stormwater runoff from low-impact disturbance
drainages was not available in the Tahoe Basin, so this project investigated the performance of
two hydrodynamic devices and one passive vault for treating runoff from a typical single family
residential neighborhood in the Lake Tahoe Basin. Assessments were conducted in two
successive years by measuring the input and output concentrations and loads, and then
comparing these results to the mass of solids and nutrients removed with annual vault cleanouts.
It was estimated that these vaults were removing from 59–95% of the solids, 23–75% of the total
nitrogen, and 7–18% of the total phosphorus. As expected, the removal rates for dissolved
nitrogen and phosphorus were relatively low, highly variable and sometime negative. Several
recommendations were provided on the appropriate locations, use and maintenance for these
types of stormwater treatment vaults at Lake Tahoe.
Lake Tahoe TMDL Phase II - Lake Tahoe Basin
Lahonton Regional Water Quality Control Board
Phase II of the Lake Tahoe TMDL consists of identifying and quantitatively testing potential
pollutant control options (PCOs) that could collectively provide the necessary nutrient and
sediment load reductions to restore 30 feet of Lake Tahoe’s renowned clarity. The potential load
reduction evaluations are being addressed across pollutant source categories responsible for
pollutant routing to Lake Tahoe and include atmospheric, streams, urban runoff, forested uplands
and groundwater. Dr. Beck and her 2NDNATURE team are the technical lead consultant for the
groundwater source category group. 2NDNATURE is also a technical consult for the urban
stormwater and stream channel loading source category groups. Over the duration of the project,
2NDNATURE will collaborate with the TMDL Watershed modeling group to improve the
models’ representation of subsurface nutrient fate and transport. Once existing conditions are
better constrained, modeling and empirical evaluations will be employed by 2NDNATURE to
quantitatively compare a gamut and pollutant control options based on implementation costs and
annual anticipated nutrient and fine sediment load reductions.
Village Green Pilot Project Phase II – Incline Village, NV
Nevada Tahoe Conservation District (NTCD)
2NDNATURE is addressing management questions regarding the impacts of fertilized land use
on water resources in the Lake Tahoe Basin. The objective of the study is to provide a complete
annual and seasonal evaluation of the nutrient treatment capability and potential downstream
impacts of a wet basin BMP that accepts runoff from a fertilized ball field. Using automated
instrumentation and advanced data collection techniques, site evaluations include detailed water
budget, nutrient cycling in surface waters, nutrient impact to shallow groundwater, nutrient
loading changes due to fertilizer and irrigation management alterations, and quantification of
- 17 -
Lake Tahoe EIP Research Proposal
detention basin modifications to improve pollutant treatment. The project has been designed to
provide scientific data that can be applied to future management of fertilized surfaces in the Lake
Tahoe Basin. It will also identify specific techniques that decrease the nutrient delivery of
fertilized surfaces on the local aquatic resources.
Lake Tahoe BMP Monitoring Evaluation Process Science Synthesis - Lake Tahoe Basin
USFS Lake Tahoe Basin Management Unit (LTBMU)
In the Lake Tahoe Basin, there is an imminent need to quantify the benefit of restoration and
pollutant treatment efforts. The Tahoe World July 7, 2005 featured article states, “After millions
of dollars have been spent on environmental restoration projects in recent decades, many are
hopeful research will soon show those projects are having a positive effect. But no one has
drawn that conclusion yet.” 2NDNATURE was retained to review and synthesize the existing
research and monitoring projects completed on Lake Tahoe stormwater BMP structures.
2NDNATURE summarized the lessons learned from these various efforts, provided a
preliminary comparison of available pollutant treatment results and developed recommendations
to improve the quality and applicability of monitoring data. The findings and recommendations
aim to improve the consistency and integration of water quality data collected within the Lake
Tahoe Basin and improve the application of these data to inform BMP design.
Surface Water/Groundwater Nutrient Study - South Lake Tahoe, CA
City of South Lake Tahoe (CSLT)
2NDNATURE has been retained by the CSLT to design and manage an extensive water quality
monitoring project at the urban Park Avenue detention basins. The BMP consists of two
consecutive basins, installed in phases over the past few years. The CSLT conducted limited
surface water and groundwater monitoring of the upper basin in the early 2000’s. 2NDNATURE
is teaming with the USGS to implement a broader assessment of both the treatment capacity of
this large urban BMP and the potential influence of infiltration of urban waters on the shallow
groundwater quality. The project includes the installation and monitoring of numerous
upgradient and downgradient monitoring wells, in-basin lysimeters, surface water monitoring
stations and continuous water level recorders. Possible solute tracer experiments and slug tests
will improve the overall understanding of hydrogeologic processes occurring at this site. The
products will include a detailed event based water budget of the Park Avenue Basins, an
evaluation of the fate and transport of key nutrient constituents introduced to this BMP, and the
quantitative evaluation of the efficiency of this project to reduce pollutant loading in urban
stormwater to Lake Tahoe.
Detention Basin Treatment of Hydrocarbon Compounds in Urban Stormwater - South
Lake Tahoe, CA
South Tahoe Public Utility District
Following a competitive bid process, South Tahoe Public Utility District retained Nicole Beck,
Ph.D. as the project manager to evaluate the potential impact of detention basin structures on
shallow groundwater quality. To reduce surface water pollutant loading to Lake Tahoe,
infiltration of urban stormwater has been a primary management practice. The goal of the project
was to determine if the chronic induced infiltration of urban stormwater may be inadvertently
polluting the South Lake Tahoe groundwater resources with hydrocarbon constituents. Since
groundwater is the local community's sole drinking water supply, this work was imperative. A
- 18 -
Lake Tahoe EIP Research Proposal
number of the city's wells have recently been closed due to low levels of MtBE. Over the 2.5
year evaluation no detections of MtBE were found in any surface water or groundwater samples
collected for this study, however Lake Tahoe Basin banned MtBE gasoline sales in 1999. The
evaluations substantiated that urban stormwater in Lake Tahoe contains elevated levels of
heavier hydrocarbon constituents, but the absence of any detections of these hydrocarbons during
recharge-based groundwater monitoring beneath two dry detention basins suggests the vertical
soil column effectively retains and removes these hydrophobic contaminants. The inclusion of
nutrient analyses during event monitoring suggests the presence of a groundwater nitrate plume
during spring snow melt in urbanized areas where infiltration is induced.
Lake Tahoe Basin Wetland Nutrient Removal Efficiency Study - Lake Tahoe Basin
Tahoe Regional Planning Agency + USEPA
As Senior Scientist at Swanson Hydrology + Geomorphology, Dr. Beck designed and managed
an extensive data collection effort. This effort evaluated the seasonal ability of three detention
basins to remove nutrients and fine sediments from Lake Tahoe Basin stormwater. The study
included quantification of pollutant stormwater loading from different land use cover types. The
treatment efficiency of each BMP, with respect to pollutants of concern, was also evaluated. The
project identified the key spatial and temporal differences of nutrient and fine sediment loads
from various land use types within the Tahoe Basin. The study also identified the annual
efficiency of CIP projects to reduce the net annual pollutant loads to local surface water
resources. The results of this project stimulated changes to the TRPA fertilization management
policy. The findings from the TRPA project also facilitated the ongoing evaluations at Village
Green Pilot Project to expand existing knowledge of the fate and transport of nutrients emanating
from fertilized surfaces.
Upper Truckee River: Upper Reach Environmental Assessment - Lake Tahoe, CA
Tahoe Resource Conservation District
While employed with Swanson Hydrology + Geomorphology, 2NDNATURE team members
conducted numerous aspects of this comprehensive fluvial evaluation. Mr. Patsch utilized the
team’s detailed topographic survey and hydrologic evaluations to develop the HEC-RAS model
of the subject riverine reach for potential enhancement alternative evaluations. Dr. Beck and Ms.
Mathias completed the hydrologic and fluvial morphologic evaluations, including a detailed
stream bank erosion potential analysis from techniques modified from Rosgen. All members
were also intimately involved in the watershed sediment source and loading analyses and the
final product generation.
Meeks Creek Watershed Assessment - Lake Tahoe, CA
U.S. Forest Service LTBMU
Dr. Beck conducted the hydrologic analysis and water quality portions of the Meeks Creek
Watershed Assessment performed by Swanson Hydrology + Geomorphology. The water quality
assessment included soil core extraction from Meeks Marina to document historic pollutant and
ecological impacts of the natural wetland removal and current Meeks Marina operation. Pore
water samplers were utilized to document spatial and temporal trace metal enrichment as a result
of Marina operation. Targeted monthly sampling of the Marina and surrounding waters were
utilized to document the annual nutrient and carbon cycling within the Meeks Marina relative to
other Lake Tahoe Lagoons that remain in a naturally functioning state. Mr. Patsch developed a
- 19 -
Lake Tahoe EIP Research Proposal
HECRAS model of the lower Meeks Creek Watershed to identify floodplain surfaces and model
the hydrologic and hydraulic response of the system to a variety of potential channel
modification alternatives.
- 20 -