Benefit-Cost Analysis of Water Quality Investments for Coastal California Involving Human Health and Recreation

Transcription

1 Benefit-Cost Analysis of Water Quality Investments for Coastal California Involving Human Health and Recreation Mark Buckley ACES 2018 December 5, 2018

2 Overview and Context Municipalities face billions of dollars in water quality compliance costs E.g. $49 billion for NYC, $ billions for Seattle, Los Angeles. Small communities proportionately. Affordability analyses suggest communities have a budget constraint on water quality compliance costs ~2% of median household income, requires consideration for distributional/diversity issues. Diminishing returns to water quality investments MC $ MB Q 2

3 Do all WQ investments make sense? Review finds C > B for most WQ CBAs (avg. B:C 0.37) For decades, the benefits of CWA compliance were self-evident. Low-hanging fruit in some contexts largely picked. Ongoing investments must be strategic. 3

4 Wet Weather Bacteria TMDL Recreational water quality standards based on illnesses per exposure (2012 criteria 32 to 36 illnesses per 1000 exposures) Should they hold during wet weather? Orange Co., San Diego Co., City of San Diego face $billions to meet WQS during wet weather Are these investments best use of available funds for WQ? 4

5 Wet Weather Bacteria TMDL CBA Team Effort Surfer Health Study (SCCWRP & Soller Environmental) Stormwater BMP modeling (Tetra Tech) Riparian restoration BMP modeling (ESA) Sewer, septic, homeless camp modeling (Brown & Caldwell) Cost Benefit Analysis (Environmental Incentives and ECONorthwest) Steering committee of co-permittees, USEPA, SD RWQCB Analysis of benefits and costs of several possible strategies Technical Advisory Committee chaired by Ken Schiff (SCCWRP) Steering Committee, funding by co-permittees 5

6 Overview of Analysis Scenarios each alter an aspect of TMDL implementation Scenario bacteria concentrations are used to find illness rates Benefits analysis finds values for avoiding illnesses, regaining beach days and co-benefits of BMPs Cost analysis finds costs for BMPs to achieve scenario goals Results convey findings for total benefits, cost-effectiveness and net benefits Primary/Direct Benefits (All quantified and monetized) Avoided Illness (gastrointestinal and all infectious illness) Additional Beach Trips Co-Benefits (Bold quantified and monetized) Water Supply Carbon Sequestration Air Quality Property Values Human Health and Well-Being Flood Control Wildfire Risks Riparian Habitat Recreation and Amenities Other Pollutant Removal Only likely (not potential) benefits quantified or described. Human Sources scenario secondary effects 6 not defined sufficiently for quantification.

7 Public Health Benefits Compiled all available beach attendance data Including daily data and visitor type Developed statistical (econometric) model of exposures (surfers and swimmers) on wet days (storm, storm +1, +2, +3) Used peer-reviewed value of avoided illnesses based on literature review including willingness-to-pay, healthcare costs, and lost work/leisure time. BENEFIT VALUE (LOW) VALUE (HIGH) Avoided GI Illness $78.9 $263 Avoided Any Non-GI Infectious Illness $78.9 $2,630 7

8 Recreation Benefits Calculated forgone trips based on beach attendance data for non-storm wet days Included all beach visitors (surfers, swimmers, and non-swimmers) Calculate change in safe wet days Trip value based on peer-reviewed survey-based study from San Diego County 8

9 Beach attendance data and modeling for daily estimates Applied all available beachspecific attendance data (daily, weekly, monthly, annual) Extrapolated with controls for beach type, geography ln AAAAAAAAAAdd iiii = αα 0 + αα 1 WWWWWWWWWWWWYY tt + αα 2 MMMMMMMMHH tt + αα 3 BBBBBBBBHH ii + αα 4 PPPPPPPPPPPP iiii + αα 5 TTTTTTPP iiii + αα 6 RRRRRRNN iiii + αα 7 CCCCCCCCCCYY iiii + αα 8 RRRRRRRR1 iiii + αα 9 RRRRRRRR2 iiii + αα 10 RRRRRRRR3 iiii + αα 11 RRRRRRRR4 iiii + αα 12 RRRRRRRR5 iiii + εε iiii 9

10 Annual wet weather beach trips and exposures small share of total 160,000, ,868, ,000, ,000, ,000,000 80,000,000 60,000,000 40,000,000 20,000,000-4,985,692 1,164,642 1,153,614 17,703 10

11 Baseline illness rates are low, and don t change much with BMPs Storm Day GI Storm +1 GI Storm +2 GI Storm +3 GI Storm Day All Other Storm +1 All Other Storm +2 All Other Storm +3 All Other 0 BASELINE 2010 TMDL STREAM: +MS4 San Diego County, per 1000 exposures 11

12 Efforts targeting human pathogen sources have much more effect GI All Other BASELINE HUMAN SOURCES: HIGH HUMAN SOURCES: HIGH+MED Average of all watersheds, per 1000 exposures HUMAN SOURCES: HIGH+MED+LOW 12

13 Change in unsafe swimming days follow similar patterns Storm +1 Storm +2 Storm BASELINE 2010 TMDL HUMAN SOURCES: HIGH San Diego County Data STREAM: +MS4 13

14 Avoided illnesses over 65 year timeframe are highest for direct human source pathogen control AVOIDED INFECTIOUS ILLNESSES (THOUSANDS) 2,250 1,640/471 San Diego County 2,000 1,530/415 Orange County 1,750 1,280/345 1,500 1,250 1, /6 105/6 0 2/3 11/3 34/3 89/5 98/5 2/5 24/21 44/24 36/24 14

15 Scenario costs ~$1-$8 billion COSTS BY CATEGORY ( , 3% discount rate) COST (MILLION $) $9,000 $8,000 $7,000 $6,000 $5,000 $4,000 $3,000 $2,000 $1,000 $- Programmatic Operation & Maintenance Capital Total Cost 15

16 Quantifiable net benefits are negative (including co-benefits) NET BENEFITS NET BENEFITS (MILLION $) $0 -$1,000 -$2,000 -$3,000 -$4,000 -$5,000 -$6,000 -$7,000 -$8,000 Stormwater Schedule Human Sources Stream 16

17 Human source pathogen targeting is most cost-effective PUBLIC HEALTH COST-EFFECTIVENESS 1, AVOIDED INFECTIOUS ILLNESSES PER 1 MILLION DOLLARS INVESTED

18 Conclusions All water quality investments don t necessarily make sense TTTTTTTTTT bbbbbbbbbbbbbbbb mmmmmmmmmmmmmmmm bbbbbbbbbbbbbbbb Regulatory compliance should: Determine local overall WQ budget (household and business affordability) Identify locally highest value, most scarce water quality uses Evaluate most cost-effective structural and non-structural strategies across all pollutants and constraints 18

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