City of Tallahassee Wastewater Treatment System Hydrogeology Workshop – 2005 May 12 – 13, 2005

Description of System   Population Served – 170,000+ Treatment Plants:        LBR – 4.5 mgd TPS – 27.5 mgd Total = 32 mgd Effluent Discharges: SWS – 1.04 mgd SEF – 27.39 mgd Total = 28.43 mgd

Southeast Farm

City’s Wastewater Treatment System Highly Regulated     FAC 62-610 – Reuse, including land application FAC 62-600 – Wastewater Treatment Facilities FAC 62-601 – Wastewater Monitoring 503 Rule – Federal Biosolids regulations Myriad others regarding safety, chemicals, stormwater, etc.

Chapter 62-610, F.A.C.

  Created in 1989 Earlier Rules From 1980     Revised in 1999 Comprehensive Detailed Consistent With National Guidelines

Ground Water Standards    

Potable Ground Water

 

Drinking Water Standards Primary Standards Secondary Standards Total Coliforms < 4/100 mL Nitrate - 10 mg/L (as N)

Other Controls  

Monitoring

 

Reclaimed Water Ground Water Operator Staffing

 

Access Controls Storage

Zone of Discharge

Land Application 100 ft.

Ground Water Flow Monitoring Wells

SEF Monitoring Wells

Total Nitrogen from TPS, Lbs.

Total Lbs N/M onth from TPS, 1995-2003

80000 70000 60000 50000 40000 30000 20000 10000 0 LBS

600 500 400 300 200 100 0

Nutrient Uptake Rates for Selected Crops

NITROGEN Alfalfa Sweet Clover Soybeans PHOSPHOROUS POTASSIUM Coastal Bermuda Corn Cotton Ryegrass Grain Sorghum

Estimated N Allowable at SEF   Total acres in pivots = 2000 80% in bermuda grass @ 400 lbs. N     10% in corn @ 210 lbs. N 10% in other crops @ 150 lbs. N Total N allowed per year = 712,000 lbs.

Or 1950 lbs/day average

SE Farm Pond Effluent

Nitrate + Nitrite 1983-2002

35.00

30.00

25.00

20.00

15.00

10.00

5.00

0.00

1/ 13 /1 98 3 10 /7 /1 98 5 3/ 25 /1 98 7 8/ 21 /1 98 8 2/ 19 /1 99 0 7/ 31 /1 99 1 1/ 6/ 19 93 6/ 27 /1 99 4 12 /1 1/ 19 95 9/ 24 /1 99 7 3/ 10 /1 99 9 8/ 23 /2 00 0

Date Collected

Successes in Reducing Nitrogen Loads      Stopped applying biosolids in Wakulla County 2001 Start-up of Class A dryer March 2004 85% reduction of total biosolids land applied at airport 85% Class A product or Class B to landfill Obtaining more N reduction at TPS effluent

City Actions in Finding Solutions     USGS Study - $495 K over three years Treatment Master Plan – Review treatment and disposal options for long-term sustainability Planning additional biosolids treatment to produce 100% Class A Biosolids for reuse Nutrient Management Plan for near-term Farm Operations

Economic Impacts     $66 million proposed to upgrade TPS Additional $millions for full nutrient removal (2 ppm nitrates) Could lead to large rate increase Does not include O&M costs

1.

2.

3.

4.

Water Utility Approach 5.

Collect Data Develop Alternatives through Master Plan Prepare Plan of Action for Improvements Obtain Funding & Implement Near-term Items Participate in TMDL process to fine-tune Plan of Action and priorities

TMDL Schedule for Wakulla River  

2007 - Begin developing TMDL 2008 - Adopt TMDL by rule (APA)

 

2009 - Establish TMDL implementation plan 2010 – Implementation