Nutrient Criteria and Strategies Adventures in Science-based Policy II Chris Zell, PHWQ Geosyntec Consultants REGFORM Water Seminar September 5-6, 2013 Columbia, Missouri
Jun 22, 2015
Nutrient Criteria and Strategies Adventures in Science-based Policy II
Chris Zell, PHWQ
Geosyntec Consultants
REGFORM Water Seminar
September 5-6, 2013
Columbia, Missouri
Nutrient Session Outline
Chris -
Nutrient Criteria and Management Issues
• National Drivers
• Reduction Strategies
• Numeric Criteria (N, P, and algae)
• Point and Non-point Source
Treatment
• Nutrient Trading
Karen -
Regional and National Nutrient Policy Issues
National Drivers
Clean Water Action Plan
Chesapeake Bay TMDL
Mississippi River Basin & Gulf
Hypoxia
Legal Challenges/Petitions
Nutrient Criteria Low #’s, High Costs
Nutrient Reduction Strategies,
TMDLs and Permits
Reducing and Managing Nutrients
‘Option’ A - Nutrient Reduction Strategies
March 16, 2011 EPA Memo from Nancy Stoner
Includes an 8 element nutrient reduction strategy
Comparable efforts underway or completed in some
states (e.g., KS, MS, LA)
1. Prioritize watersheds
2. Set watershed load reduction goals
3. Ensure effective point source permits
(including CAFO, MS4)
4. Target most-effective Ag BMPs
5. ID tools for small on-site systems and runoff
6. Accountability and verification measures
7. Public reporting
8. Develop nutrient criteria work plan & schedule
Planning
Accounting
Reducing and Managing Nutrients
Example Nutrient Reduction Strategies
Kansas – adopted nutrient reduction plan in 2005
Watershed Restoration Action Plans (WRAPs)
More than 40 nutrient TMDLs established
Point source nutrient reductions (POWTs > 1 MGD)
(1.5 mg/L ~ TP, 8 mg/L ~ TN with BNR, as annual averages)
Quantified nutrient reductions in agriculture runoff
Reduction reporting critical to NNC schedule & lawsuits
Setting Expectations – restoration pending: (1) funding
mechanisms and (2) socio-ecological response times
Wisconsin
- developed in response to Gulf Hypoxia
Action Plan (2008)
~ 45% reduction in nutrients to Gulf (1995 as baseline)
- PRESTO tool available to estimate US NPS loads
Reducing and Managing Nutrients
Example Nutrient Reduction Strategies
15-year schedule
Interim TP limit of
0.6 mg/L may
apply.
Reducing and Managing Nutrients
Example Nutrient Reduction Strategies
Missouri – In Progress
Approximately bi-monthly meetings coordinated by
Steve Walker
Table of Contents (outline): August – December 2012
More than 90 stakeholders representing over 30 organizations
Document preparation - MU and Lincoln University
Nutrient Reduction Strategies – Poll (8/20/2013)
51 questions, 19 participants
2 11.11%
2 11.11%
0 0%
2 11.11%
11 61.11%
1 5.56%
Totals 18 100%
1.) Strategy 1 Implement nutrient management plans
on all cropland acres which include the 4Rs (right source,
right rate, right time, and right place). (multiple choice) Responses
Strongly Oppose
Moderate Opposition
Neutral
Moderate Support
Strongly Support
No Opinion
Reducing and Managing Nutrients
‘Option’ B – Numeric Nutrient Criteria
Element 8 of nutrient reduction strategy is Numeric
Nutrient Criteria (NNC)
Intended to reduce occurrence of:
Condition Use
Objectionable Color
or Bottom Deposits Narrative
Low Transparency Recreation and/or Aesthetics
Algal Bloom
(O2 depletion) Aquatic Life
Algal Bloom
(Community Composition) Aquatic Life
Change in
structure or
function ?
How are NNC Developed?
Approach Description
Percentile or Reference
Approach
Statistical Frequency Analysis
(75th Percentile of Reference Streams to 25th
Percentile of All Data)
Water Quality Modeling Model algal biomass in response to nutrient
loads (QUAL2K, WASP, regressions etc.)
Ecological Stressor-Response Statistical or process-based modeling of
changes in bioindicator(s) to nutrient loads.
Composite
(aka, Weight-of-Evidence)
Multiple approaches to arrive at a range or
matrix of nutrient endpoints. Criteria may be
described as range or single value based on
strength of corroboration.
Percentiles are Problematic...
Reducing and Managing Nutrients
NNC Challenges
Percentile Approach
Subecoregional values applied as wasteload allocations in several recent Missouri
TMDLs. Default values listed as federal WQ standards are percentiles.
Ecoregional Nutrient
*Benchmark - Rivers
Ecoregion 9
(Northern Mo)
Ecoregion 10
(Missouri Bootheel)
Ecoregion 11
(Ozarks)
Ecoregion 6
(NW Missouri)
Total Phosphorus
(µg/L) 37 128 10 76
Total Nitrogen
(µg/L) 700 760 310 2180
Sestonic Chl-a (µg/L) 1 2 2 3
Periphyton Chl-a
(mg/m2) 20 N/A N/A N/A
*Aggregated Ecoregional 25th Percentiles
Water Quality Modeling
Algal Biomass Endpoints
The reality of co-limitation
Periphyton = Photo – Respiration – Death – Grazing – Scour
Co-limited by: light and nutrient supply (and substrate)
Some systems may be more sensitive to changes in light,
grazing or scour than nutrients – on an annual basis
79
27
64
77
38
29 30
3
19
6
19
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10
20
30
40
50
60
70
80
90
Site 1 Site 2 Site 3 Site 4 Site 5 Site 6
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Less-Shaded
Shaded
Reducing and Managing Nutrients
NNC Challenges
Stressor - Response
Uncertainty and Error Propagation
That is, the dose-response relationship is variable
and may be waterbody specific ($$$ science)
Source: WEFTEC 2010, Watershed Workshop. US EPA
Reducing and Managing Nutrients
NNC Challenges
An Ecological Stressor-Response Example
Ohio’s newly minted Trophic Index Criterion (TIC)
Reducing and Managing Nutrients
NNC Challenges
An Ecological Stressor-Response Example
Ohio’s newly minted Trophic Index Criterion (TIC)
Default limits if Trophic Index is not acceptable:
TP = 1.0 mg/L and DIN = 10 mg/L
If not acceptable after two permit cycles then: TP < 0.3 mg/L (use and habitat dependent)
DIN = 3 mg/L
Reducing and Managing Nutrients
NNC Challenges
Achievability and Costs
Stormwater
Reducing and Managing Nutrients
NNC Challenges
Achievability and Costs
Domestic Wastewater
Nutrient Raw Wastewater
Secondary Effluent
(no removal)
Advanced
Treatment
(BNR)
Enhanced
Nutrient
Removal (ENR)
Limits of
Technology
(LOT)
Total Phosphorus
(mg/L) 4 - 8 4 - 6 1 0.25 - 0.50 0.05 - 0.07
Total Nitrogen
(mg/L) 25 -35 20 – 30 10 4 - 6 3 - 4
From WERF Limits of Technology and Research on Nutrient Removal Webinar, October 8, 2008
Missouri Innovative
Nutrient Trading Project
USDA NRCS, St. Louis
MSD, MCGA, ERC, MPUA,
MDNR
Assist in Developing
Trading Procedures
Improve Water Quality
Provide Regulatory
Flexibility
Lower Compliance and
Abatement Costs
Simulated Trading Exercise
What is Water Quality Trading?
Market-Based Compliance System Whereby One Discharger Buys or Sells Pollution Credits from Another Point-to-Point
Point-to-Nonpoint
Tool to help meet water quality goals at a lower cost
sooner than might otherwise occur
fit within other infrastructure needs
multiple benefits
Requires flexible implementation of stream criteria
Credit Supply and Demand Curve
Total nutrient abatement cost decreased by $1.4 million annually
Nutrient Trading – Key Findings
1. Trading areas should be maximized
2. Feasibility is sensitive to trading ratio
3. Point-to-point trading can be the most cost-effective WQT
- this includes Big Rivers
4. WWTPs should be able to set the cap for trades
- technology-based limits may limit cost-effectiveness for a WQT program
($/lb abated)
5. An exchange or clearinghouse may be needed to minimize transaction costs.
6. Liability, monitoring, and enforcement could prohibit WQT
7. Raising agricultural baseline would reduce cost-effectiveness and the number
of WQT partners
End of pipe vs. watershed-based NNC is key!
Take Home Summary
A successful nutrient reduction strategy is a flexible
approach for reducing nutrient exports....and may serve
as a buffer against early adoption of NNCs.
NNCs:
- are developed according to 3 basic approaches
- are generally: (1) currently not attainable and/or (2) currently
not affordable by most sectors
- An approach that recognizes uncertainty and embraces
biological confirmation appears promising (FL, OK, others)
A successful WQT program can improve abatement
efficiency...if NNC or NRD are flexibly implemented
Thank You!
For further information:
Chris Zell, PHWQ
Geosyntec Consultants
1123 Wilkes Blvd., Suite 400
Columbia, Missouri 65201
Phone: 573.443.4100
Email: [email protected]