190 likes | 342 Views
Comprehensive Benefit Analysis of the Chesapeake Bay TMDL Presented by Elena Besedin. Comprehensive Benefit Analysis of the Chesapeake Bay TMDL. BMP Effects. Direct Effects Nutrient load Sediment Load. Indirect Effects Air pollutant release Vegetation/open space
E N D
Comprehensive Benefit Analysis of the Chesapeake Bay TMDL Presented by Elena Besedin
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 Models Water Quality Aquatic Ecosystem Fisheries Model Models Vegetation effects on air Hydrological Models Flood risk models Human health risk Monetization approaches
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)
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
Direct TMDL Effects: Nutrient and Sediment Load Reductions Nutrients 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 AlgaeTurbidity O2 LightBenthic Production RedoxNitrification UptakeSuspension Nutrient Recycling
Direct TMDL Effects: Nutrient and Sediment Load Reductions Nutrients Sediment reductions improve many factors: • Increased Water Clarity • Direct effects on benthic primary production, macroinfaunaldiversity 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 AlgaeTurbidity O2 LightBenthic Production RedoxNitrification UptakeSuspension Nutrient Recycling
Indirect TMDL Effects Example BMPs 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 • 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
Bringing the Pieces Together: Example Framework for Estimating TMDL Benefits Simplified representation showing only selected components of the analysis.
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
Human Health Effects from Reduced Air Pollution (Example) Population Distribution by Age and Presence of Sensitive Subgroups For each subgroup and baseline and post-regulation: Pollutant exposure distribution Adverse health effects distribution $ Monetary Value of Health Effects BenMap (EPA_OAQPS)
Flood Analysis Approach (Example) $ • 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
Market-based Approaches 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 • 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
Nonmarket Valuation Water Quality 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 • 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
Nonmarket valuation Air 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 • 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)
Value of Ancillary Services from Urban BMPs for Chesapeake Bay Watershed EPA/ORD analysis, 2011
Example Cost-Effectiveness of BMPs with and without Ancillary Benefits
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