Upload
randolf-warren
View
217
Download
0
Tags:
Embed Size (px)
Citation preview
Comprehensive Benefit Analysis of the Chesapeake Bay TMDL
Presented by
Elena Besedin
Abt Associates | pg 2
Comprehensive Benefit Analysis of the Chesapeake Bay TMDL
BMP Effects
Direct Effects Nutrient load Sediment Load
Indirect Effects Air pollutant release Vegetation/open space
Hydrology
ModelsWater Quality
Aquatic EcosystemFisheries Model
ModelsVegetation effects on air
Hydrological ModelsFlood risk models
Human health risk
Monetization approaches
Abt Associates | pg 3
Benefits of the Chesapeake Bay TMDL: Previous Analyses
Benefit categories included in previous analyses (M. Cropper and W. Isaac, 2011)
– Commercial fishing
– Water-based recreation (fishing, swimming, boating
– Property values
– Nonuse values
Ancillary benefit categories (EPA/ORD)
– Carbon sequestration
– Air pollutant removal (screening level)
Abt Associates | pg 4
Comprehensive Analysis of the Chesapeake Bay TMDL Including additional benefit categories
– Modeling additional ecological effects and ecosystem services provided by Chesapeake Bay and BMPs to reduce nutrient loadings beyond those accounted for in previous analyses
Modeling additional market effects
Estimating potential employment effects
Including additional services and other economic effects in benefit-cost analysis
– Accounting for costs and benefits based on TMDL implementation timeline
• Phased controls: 60% of actions by 2017; 100% by 2025
• Potential to evaluate costs and benefits over implementation timeline
– Potential for optimization of BMPs accounting for additional ecosystem service benefits
Abt Associates | pg 5
Direct TMDL Effects: Nutrient and Sediment Load Reductions
Nutrient reductions impacts:
Reduced Algal Blooms– Increased nutrient retention, benthic infauna,
community composition, increased oxygen availability, increased water clarity and light transmission
Increased Oxygen Availability– Direct effects on frequency of hypoxic events,
macroinfaunal diversity and biomass, increased bivalve populations and filtration rates, nutrient cycling, fisheries productivity
Decreased Acidification– Population and growth effects of major calcifiers,
altered vital rates, community composition
Nutrients
Algae Turbidity
O2
Light Benthic
Production
Redox Nitrification
Uptake Suspension
Nutrient Recycling
Abt Associates | pg 6
Direct TMDL Effects: Nutrient and Sediment Load Reductions
Sediment reductions improve many factors:
Increased Water Clarity– Direct effects on benthic primary production,
macroinfaunal diversity and biomass, shift in relative importance of demersal (increase) and pelagic (decrease) food webs
Increased Submerged Aquatic Vegetation (SAV) Area– Positive feedback with particle trapping and
sediment binding, reduced efflux of sediment nutrients, increased nutrient assimilation, increased oxygen production
Nutrients
Algae Turbidity
O2
Light Benthic
Production
Redox Nitrification
Uptake Suspension
Nutrient Recycling
Abt Associates | pg 7
Indirect TMDL Effects
Example BMPs Land Management
– Agricultural land retirement
– Tree planting
– Forest buffers
– Grass buffers
Natural area restoration– Wetland restoration
– Stream restoration
Agriculture– Erosion control (buffer zones)
– Animal waste management
Urban Stormwater Management – in impervious cover
Non-Water Quality Effects Land
– in open space / vegetated areas
– in the number of trees
– in riparian habitat / wetlands
Hydrology – in on-site water storage
– in groundwater recharge
– in flood risk
– stream channel protection
Air effects– reduced ammonia releases
– air pollutant removal by vegetation
– in temperature extremes
Abt Associates | pg 8
Identifying and Evaluating Ecosystem ServicesEcosystem Service
Category Water Quality Changes Ancillary BMP Services
Provisioning • Habitat for fish/shellfish consumed by humans
• Drinking water supply• Agricultural and industrial water supply• Navigation
• Riparian/terrestrial habitat for fish and game consumed by humans
• Provision of wood and other forest products• Drinking water supply (groundwater)
Cultural Water-based Recreation• Swimming• Fishing• Hunting• Boating• Near water activitiesAesthetic (water clarity/color)• Property values • Scenic vistasNonuse• Habitat preserving aquatic biodiversity
Land and Near Water Recreation• Fishing and shellfishing• Hunting (waterfowl and game)• Birding• Hiking/nature enjoymentAesthetic (landscape effects)• Property values • Scenic vistasEducation• Wetlands/forest education centersNonuse• Habitat preserving wildlife and plant
biodiversity
Abt Associates | pg 9
Identifying and Evaluating Ecosystem Services (continued)
Ecosystem Service Category Water Quality Changes Ancillary BMP Services
Regulating • Nutrient cycling• Primary production• Hypoxia events• Ecosystem resilience• pH• Water Clarity
Air• Air pollutant releases (ammonia)• Air pollutant removal by vegetation• Carbon storage• Reduction in air temperature volatilitySoil• Erosion control• Sediment retentionHydrology• Flood control• Stream bank stabilization• Stream channel protection• Groundwater rechargeWater Quality• Filtration/Nutrient removal (groundwater)• Reduction in stream temperature volatility
Abt Associates | pg 10
Bringing the Pieces Together: Example Framework for Estimating TMDL Benefits
Simplified representation showing only selected components of the analysis.
Abt Associates | pg 11
Effects of Increased Vegetation: i-Tree Model, US Forestry Service
i-Tree is a peer-reviewed model developed by the USFS– Estimates services from trees and shrubs
– Use field data or GIS layers for tree canopy and impervious surface
Air Pollution Removal (PM10, PM2.5, NO2, SO2, CO, O3)
– Pollution removal per unit of tree canopy based on local conditions
– Can be converted to changes in concentrations
Carbon Sequestration and Storage– Sequestration and storage per unit of tree canopy
Energy Savings– Shading and windbreak savings based on tree placement
Can be supplemented with data for other vegetation types
Abt Associates | pg 12
Human Health Effects from Reduced Air Pollution (Example)
$Monetary Value of Health Effects
For each subgroup and baseline and post-
regulation:
Pollutant exposure distribution
Adverse health effects distribution
Population Distribution by Age and Presence of Sensitive Subgroups
BenMap (EPA_OAQPS)
Abt Associates | pg 13
Flood Analysis Approach (Example)
Channel/Floodplain assumptions in SWAT, Manning’s Equation
Flood Depths
SWAT
Flood Zone Estimation
NFRST
GIS Data
Flood Hazard (Flood
Frequency Analysis)
Flood Depth Estimation
Flows Flood Flows
Floodplain Areas per Census Block
Stream lines Census Block
Channel/Floodplain assumptions in SWAT
Flood Impacts
Updated HAZUS-HM Inventory in 2040
SWAT: Soil and Water Assessment Tool developed by USDA HAZUS-MH: Hazards U.S. Multi-Hazard (HAZUS-MH) Tool developed by FEMA NFRST: National Flood Risk Screening Tool developed by Abt Associates
$
Abt Associates | pg 14
Market-based Approaches
Water Quality – Commercial fish/shellfish harvest
– Drinking water treatment
– Reservoir dredging
– Navigational waterways dredging
– Agricultural/industrial water supply
Air – Electricity savings
– Technology alternatives to carbon sequestration
– Technology alternatives to air pollutant removal
Employment Effects Regional Economic Impacts
– Input output models
Hydrological Benefits– Flood damages
– Groundwater quantity
– Drinking water treatment (groundwater)
– Avoided cost of infrastructure maintenance and expansion
– Avoided cost of stream restoration
– Water storage for beneficial use
Abt Associates | pg 15
Nonmarket Valuation
Water Quality Water-based recreation
– Recreational demand models
– Stated preference (SP) studies
– Hedonic studies
Human health (e.g., exposure to pathogens in shellfish, drinking water or while swimming)
– Cost of illness
– SP studies
– Averting behavior
Aesthetic– Hedonic property
– SP studies
– Recreational demand
Nonuse values (aquatic life support, biodiversity, overall ecosystem health and resilience)
– Stated preference studies
Landscape Land (including wetlands)
– Land-based recreation
• Recreational demand models
• SP studies
• Hedonic studies
– Aesthetic
• Hedonic property
• SP studies
• Recreational demand
– Nonuse (wildlife habitat, biodiversity)
• SP studies
Abt Associates | pg 16
Nonmarket valuation
Air Human health
– Exposure to criteria pollutants (mortality and morbidity)
• Cost of illness
• Stated preference studies (BT)
– Exposure to extreme temperature (mortality)
• SP studies
Carbon sequestration• Social Cost of Carbon (SCC)
Hydrology Flooding (value of reduced flood
risk)– SP studies
– Hedonic property models
Groundwater protection– SP studies
– Averting behavior
Stream channel protection– SP studies
– Hedonic property models
Abt Associates | pg 17
Value of Ancillary Services from Urban BMPs for Chesapeake Bay Watershed
EPA/ORD analysis, 2011
Abt Associates | pg 18
Example Cost-Effectiveness of BMPs with and without Ancillary Benefits
Abt Associates | pg 19
Challenges, Gaps, Overlaps Quantification
– Lack of data or models to estimate ecological improvements (e.g., ecosystem resilience, stream channel stabilization)
– Some beneficial effects are omitted from the water quality modeling step (e.g., pathogens)
– Timeline for TMDL implementation
Monetization
– Linking ecological and economic endpoints
– Selecting ecological metrics that provide an accurate representation of ecosystem change
Measurable Comprehensive
Interpretable Applicable
– Potential overlapping and double counting of benefits
Property value change vs. recreational benefits
Property value change from improved landscape vs. water quality
– Capturing multi-media effects
Selecting an optimal set of BMPs: cost-benefit optimization framework