Orange County: A Regulated Agency Perspective on TMDLs

1
Orange County A Regulated Agency Perspective on
TMDLs

• Larry McKenney,
• Watershed Coastal Resources Division

2
Orange Countys Experience

• Upper Newport Bay/San Diego Creek
• Sediment
• 50 load reduction in Bay by 2009
• NMT 1 habitat acreage change due to sediment
  deposition
• Nutrients
• N and P
• Algae
• Fecal coliform
• REC-1 by 2013
• SHEL by 2019
• Toxics
• OP Pesticides
• Selenium
• Metals
• Organochlorine compounds

3
Why Do We Have TMDLs?

• To protect and restore beneficial uses that are
  impaired by water quality despite full
  implementation of the NPDES
• In other words, where the mandated
  standards-and-permits approach is failing, TMDLs
  are the backstop

4
Implications

• TMDLs perhaps should not be bound by the same
  logic of water quality that is already failing to
  protect the use (e.g. single constituent mass
  balance)
• TMDL implementation plans need to focus on the
  uses, not the existing standards
• TMDLs are most likely to happen in situations
  where knowledge about the water body starts
  small and grows quickly
• TMDLs are a means, not an end
• Therefore, implementation of TMDLs should be an
  adaptive process

5
Urban Myth TMDLs are Based on Science?

• Decisions about impairment often incorporate
  earlier necessary assumptions embedded in Basin
  Plans
• TMDLs are rarely based initially on good data
• TMDLs usually address one pollutant and one
  problem in isolation
• Legal issues driving TMDLs may preclude
  dispassionate objectivity
• Are we willing to learn as we go and act on the
  lessons?

6
Some Key Issues

• Monitoring
• There is too much unfocused, uncoordinated
  monitoring
• We need to spend our monitoring resources on
  questions that need answers, and then move on
• We need to define success
• Keeping our eyes on the ball uses!
• TMDLs should be done at some point?
• Systems Approach
• Watershed is not just a word