Water Quality Standards at Caddo Lake

1
Water Quality Standards at Caddo Lake

• Environmental Flows Workshop Planning Meeting
• May 2007

2
Two Recent Proposals

• 1. Proposal to change the segments and related pH
  issues
• 2. Delisting or Downgrading
• - TCEQ proposed changes to 303(d) listings for
  segments 401, 402, and 407

3
Current Segments

• Map will go here.

4
Proposal to change segments and related pH issues

• Arthur Crowe to Caddo Lake Institute on March, 26
  2007 (abbreviated)
• TCEQ staff would like to offer several ideas for
  discussion regarding Caddo Lake during the
  current triennial standards review
• 1. Change the boundary description between 0401
  and 0402 to read the intersection of Big Cypress
  Bayou and Government Ditch in the Devils Elbow
  area. This is a clearer description than the
  current boundary which is a certain distance
  downstream of SH43
• 2. Divide segment 0401 into two separate
  segments with the upper area referred to as The
  Caddo Swamp (see next slide). The two areas are
  different physically and hydrologically.
• 3. The Caddo Swamp to have different pH standard
  (5.5-8.5 S.U.) than that of the main lake
  (6.0-8.5 S.U.).
• We are also considering lowering pH standards
  for some other streams in the Cypress Basin that
  we feel are the result of natural conditions

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6
Delisting/Downgrading

• Draft 2006 Texas Water Bodies and Parameters
  Removed from the 303(d) List (March 19, 2007)
• Caddo Lake (401)
• Big Cypress Below Lake O the Pines (402)
• James Bayou (407)
• Little Cypress Bayou (Creek) (409)

7
Caddo Lake (Segment 401)

• Current Listed Impairment Depressed Dissolved
  Oxygen
• Current Listed Impairment Category 5c
• The water body does not meet applicable water
  quality standards or is threatened for one or
  more designated uses by one or more pollutants
• Additional data and information will be collected
  before a TMDL is scheduled

8
Caddo Lake (Segment 401)

• Reason for delisting Pollution
• This impairment is not caused by a pollutant load
  that can be allocated and controlled with a TMDL.
  This impairment has been moved to a category 4c.
• Additional Information
• The seasonal low dissolved oxygen condition in
  this portion of the lake is due to natural
  conditions with trees, wind protection, little
  water movement, and warm temperatures. A TMDL
  would not be a useful water quality planning
  strategy

9
Big Cypress (Segment 402)

• Current Impairment 1 Depressed Dissolved Oxygen
  
• Current Listed Category 5c
• The water body does not meet applicable water
  quality standards or is threatened for one or
  more designated uses by one or more pollutants.
• Additional data and information will be collected
  before a TMDL is scheduled.
• Current Impairment 2 Lead in Water
• Current Listed Category 5c (see above)

10
Big Cypress (Segment 402)

• Reason for Delisting MEETS
• The most recent set of data demonstrates that
  water quality standards are now met and water
  quality meets the requirements for delisting
• For both impairments 1 and 2

11
James Bayou (Segment 407)

• Current Impairment Copper in Bayou
• Current Category 5c
• The water body does not meet applicable water
  quality standards or is threatened for one or
  more designated uses by one or more pollutants
• A review of the water quality standards will be
  conducted before a TMDL is scheduled
• Reason for Delisting MEETS
• The most recent set of data demonstrates that
  water quality standards are now met and water
  quality meets the requirements for delisting

12
Little Cypress (Segment 409)

• Current Listed Impairments Depressed Dissolved
  Oxygen and Bacteria
• Current Listed Impairment Category 5c
• The water body does not meet applicable water
  quality standards or is threatened for one or
  more designated uses by one or more pollutants
• Additional data and information will be collected
  before a TMDL is scheduled
• No proposal to change this listing