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Recommendations and Tools for Developing TMDL Effectiveness Monitoring Plans Laura Blake, Corey Godfrey, and Andy Somor The Cadmus Group, Inc. Project Funded by U.S. EPA Region 10
Recommendations andTools for Developing TMDLEffectiveness MonitoringPlans
Laura Blake, Corey Godfrey, and Andy Somor
The Cadmus Group, Inc.
Project Funded by U.S. EPA Region 10
“Effectiveness Monitoring”
The process of measuring improvements inthe water quality of a water body.
Not to be confused with BMP effectiveness,which measures the success oreffectiveness of the BMPs themselves.
The primary goal of TMDL effectivenessmonitoring is to identify water qualityimprovements (or lack thereof) that resultfrom TMDL implementation.
Steps for Designing a TMDLEffectiveness Monitoring Plan
• Review existing data and information.1
• Select monitoring sites, parameters,and study design.2
• Estimate sample size.3
• Develop TMDL effectivenessmonitoring plan.4
Review Existing Data andInformation
Begin with thorough review of all availableinformation that may direct the process.
Existing data and information will providean understanding of:
Historical and current water qualityconditions.
TMDL implementation activities.
Involve stakeholders early.
Select Monitoring Sites,Parameters, and Study Design
Design effectiveness monitoring projects atthe watershed scale.
Specific project scale should be decidedupon using information on the number andextent of impaired or threatened waters,project resources, and project partners.
Watershed scale effectiveness monitoring:
Pour point method
Distributed sampling method
Site Selection Approach:Pour Point Method
Monitoring Site
Site Selection Approach:Distributed Sampling Method
Monitoring Site
Site Selection
Locate monitoring sites where TMDL implementation isexpected to have discernible water quality effects.
Examples include sites on impaired/degraded waterbodies that are downstream of:
WWTFs with new or revised WLAs.
Discontinued illicit discharges.
NPS that are managed through BMPs.
Stream channel restoration projects.
Improved onsite wastewater management or expansionof sanitary sewer service.
Other TMDL-related pollutant reduction measures.
Evaluate existing monitoring network or sites.
Parameters
Monitor the pollutants for which the TMDLwas developed.
Monitor for stressor and/or responsevariables, which provide additionalinformation about the condition of a waterbody.
Monitor parameters that may be covariatesto the primary pollutants of interest.
Stream flow is a common covariate forpollutants in streams and rivers.
Study Design
Outlines how water quality improvements will bedemonstrated.
Critical to ensuring the collection of the specificdata needed to answer the study questions/goals.
Selection is dependent on many factors, including:
Types of TMDL implementation actions.
Implementation schedule.
Availability and quality of previously collected data
Resources.
Existence of suitable reference sites.
Study Design Examples
Before & After
Upstream/downstream
Paired watersheds
Trend monitoring
Study Design:Before/After Study
Before After
Time
Study Design:Upstream/Downstream Study
Study Design:Paired Watersheds Study
Before After
Time
Treatment Control
Study Design:Trend Monitoring
Time
Estimate Sample Size
Water quality data are often collected withoutconsidering the number of samples needed todemonstrate statistically significant changes.
Objective and informed sample size decisionscan be made using a statistical method knownas power analysis.
Power analysis uses information from pilot datato determine the optimal number of samplesneeded to identify statistically significantchanges or trends.
Power Analysis
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Sample Size (N)
TMDL EffectivenessMonitoring Planning Tool
Develop TMDL EffectivenessMonitoring Plan
Steps for planning a TMDL effectivenessmonitoring project:
1. Review existing data and information.
2. Select monitoring sites, parameters, andstudy design.
3. Estimate sample size.
4. Develop TMDL effectiveness monitoringplan.
Develop TMDL EffectivenessMonitoring Plan (cont.)
The planning document should include:
Relevant background information.
Project goals and objectives.
Where and when monitoring will occur.
List of parameters to be monitored.
Preliminary discussion of intended dataanalysis methods, including selected level ofsignificance.
The TMDL effectiveness monitoring plan canbe incorporated into a QAPP.
More Information
EPA Region 10 website:
http://yosemite.epa.gov/R10/water.nsf/TMDLs/TMDL+Program
Questions?
Laura Blake
The Cadmus Group, Inc.
617-673-7148
Recommendations and Tools for Developing TMDL Effectiveness Monitoring Plans“Effectiveness Monitoring”Steps for Designing a TMDL Effectiveness Monitoring PlanReview Existing Data and InformationSelect Monitoring Sites, Parameters, and Study DesignSite Selection Approach:�Pour Point MethodSite Selection Approach:�Distributed Sampling MethodSite SelectionParametersStudy DesignStudy Design ExamplesStudy Design:�Before/After StudyStudy Design:�Upstream/Downstream StudyStudy Design:�Paired Watersheds StudyStudy Design:�Trend MonitoringEstimate Sample SizePower AnalysisTMDL Effectiveness Monitoring Planning ToolDevelop TMDL Effectiveness Monitoring PlanDevelop TMDL Effectiveness Monitoring Plan (cont.)Slide Number 21Questions?
