the pompano canal story
TRANSCRIPT
Part VIII The Pompano Canal Story
TMDL Monitoring & Assessment Report
Once Upon A Time..There was a Canal
Within the City of
Pompano Beach, in the
County of Broward, with
FDOT District 4 Roadways
3,795 Acres of Urban Living
In the Land Of the Broward County NPDES MS4 Permit
30 Co-Permittees
50 page long Permit
TMDL Implementation = FDEP BMAP Section
Then One Day……
The Cycle 3 Permit Arrived
102 Pages
115 Requirements
SOPs, ERPs, and TMDLs, OH MY!!!
Part VIII 3 a, the Beginning
Broward County and Co-Permittees
• TMDL Prioritization Report •Two adopted TMDLs in Broward County
•EPA Fecal Coliform •FDEP Nutrient
•Co-permittees went through a joint ranking process •Pompano Canal TMDL selected as the Cycle 3 Priority TMDL
It’s No Longer Impaired for Nutrients!
FDEP Confirmed: – Delisting for next
assessment cycle based on the annual Chlorophyll-a averages
The TMDL load reductions have been met!
Hydrological conditions a significant contributor!
The Permit Requires!!
After the TMDL
Prioritization thou shall
move to Part VIII 3 b,
TMDL Monitoring and
Assessment Plan
– Seasonal Loading
– Outfall Ranking
– Storm Event Monitoring
Storm Event Monitoring!
Multiple Outfalls
Three Co-Permitees
FDEP Required
–Each Agency Monitor an outfall
–No shared monitoring on one single outfall
Part VIII, Section B
“It is the intent of this section….. to ensure that within watersheds that
discharge to a water body with an EPA-established or DEP-adopted TMDL.”
–Pollutant discharges for those parameters listed in the TMDL are
reduced to the MEP through the implementation of the permittee’s SWMP.
–Adequate progress toward achieving assigned wasteload allocations
(WLAs) will be demonstrated through the implementation of – Structural and nonstructural best management practices (BMPs) and
– Other program activities that are targeted at TMDL-related pollutants
A Consent Decree TMDL
WMM nutrient output didn’t calibrate well The data did have a relationship with between Stormwater Runoff and Annual Rainfall –Stormwater runoff measured as
flow at the G-57 Control Structure
–G-57 is Canal Discharge Point
But it Makes Sense!
The FDEP stated that the issues with the long-term data set (Station FLBROW110) necessitated a different TMDL approach because the long term data set:
–Failed to capture information from the area of the drainage
basin that is generating the Chla exceedances,
–Did not recognize its correlation to rain events,
–Failed to provide useable relations between nutrients and Chla.
It’s a Plane, it’s a Train, It’s a Regression Model
•Loading capacity of the canal was estimated using a single regression model.
•Only two of the four FDEP “Special” sampling sites were used in the regression analysis.
•The furthest most downstream sites along the Pompano Canal and C-1 Canal were chosen because of the better correlation of TN and TP to Chla.
THE TMDL
•Adopted May 2007 •Impaired for Chlorophyll-a •Co-Limited •WLA Percent Reduction
–15.8% TN –13.6% TP
•Pounds Per Year Reduction –2,174.76 TN – 144.88 TP
TMDL
Puff the Magic Dragon
Existing Concentration –0.76 mg/L TN
–0.059 mg/L TP
Allowable Concentration –0.640 mg/L TN
–0.051 mg/L TP
The language adopted into Chapter 62-304 F.A.C., requires reductions in the existing load to meet the allowable annual load of 11,590.98 pounds (lbs) of TN and 923.66 lbs of TP.
Meeting TMDL Load Reductions
Verified Period 1998
SWMP Implementation
Significant Redevelopment –Stormwater Retrofits
•Redevelopment Pollutant Load not higher than previous land use
•Runoff Coefficent not higher because of increased perviousness
SWMP Nutrient Reductions
Redevelopment Nutrient Reductions
Bean Counting for Compliance
This is What Compliance Looks Like?
The Hydrology Problem
Looks Like a Canal but it’s really a Linear Pond!
Nutrient Reductions Met
Chla Concentrations
Lowered
TN and TP Concentrations have not Decreased
Great the Gate is Fixed But it has to Operate
The Truth Shall Set You Free!
TMDL Load Reductions
Achieved –Structural
–Non-Structural
Ambient Water Quality
Not Impaired
Root Cause Impairment
not from MS4 Discharge
Everyone Loves a Happy Ending!!
Happily Ever After?
No, Way!
This is a
Regulatory
Program
The Delisting
Water Quality Influenced by Gate Operations SFWMD Gate Operation
–Inconsistent –One May be Open and the Other
closed –SFWMD Operational Schedules
not Water Quality Driven
Status: –On Track for Delisting for Chla
(Mostly) –Dissolved Oxygen Continues to
be a Problem
The Moral of the Story
Before Gate Repair After Gate Repair
Maria Loucraft City of Pompano Beach Utility Compliance & Efficiency Manager [email protected] Amy Tracy ETM Water Resources Specialist [email protected]
Questions & Contact Information