Decentralized Wastewater Systems in Tennessee

1
Decentralized Wastewater Systems in Tennessee

• Where are we today?
• Where are we going?

2
TDEC Division of Water Pollution Control Permit
Program

• 9331 Permits Administered
• 345 State Operating Permits
• (No Discharge)
• 6120 Facilities under General Permits
• 857 Individual NPDES Permits
• 1500 Aquatic Alteration Permits
• 481 Mining-Quarry, Clay, Sand Gravel
• 28 Interbasin Water Transfer

3
Municipal and Domestic Wastewater Permits

• 584 Municipal and Domestic NPDES Discharge
  Permits
• 183 Decentralized Wastewater Treatment Systems
  (Non-Discharging)

4
Where are the Systems?
5
Systems by County

• 25 Rutherford 5 Jefferson
• 20 Wilson 5 Montgomery
• 17 Sevier 5 Roane
• 11 Williamson 4 Cumberland
• 9 Blount 4 Dickson
  
• 8 Davidson 1-3 41 Counties
• 7 Robertson

6
Who are the Permittees?

• 35 Facilities / 10 Public Utility Districts
• 17 Facilities / 1 Wastewater Authority
• 58 Facilities / 5 Privately Owned Public
  Utilities (under TRA)
• 14 Facilities / 9 County School Boards
• 17 Facilities / Private Resorts, RV Parks, etc.
• 8 Facilities / State Parks/Rest Areas

7
Size of Systems (Based on Design Capacity)
8
Decentralized Waste Treatment Permit Activity
9
Treatment Technology

• The treatment process can generally be divided
  into three parts
• Primary treatment
• Secondary treatment
• Land application

10
Treatment Technology

• Primary Treatment
• Septic Tank
• Grinder Pumps

11
Treatment Technology

• Secondary Treatment
• Recirculating Filters - 145 systems
• Lagoons - 34 systems
• Other - 4 systems

12
Treatment Technology

• Land Application
• Drip Irrigation - 153 systems
• Spray irrigation - 30 systems

13
State Permitting Requirements (Current)

• Submittal of Engineering Report and Design
  Drawings
• Use of a Trained Biological Natural System
  Operator
• Sampling and Testing of Secondary Effluent
• Flow 1/month
• BOD 1/quarter
• Ammonia 1/quarter

14
State Permitting Requirements (Current)

• Other Requirements Applied Where Applicable
• Buffers
• Fencing
• Disinfection
• E. coli Limit 23/941 per 100 ml
• BOD Limit 45 mg/l
• Nitrate Limit 10 mg/l

15
How Well Do the Systems Work?

• Past 2 Year Record for 10 Systems in Rutherford
  County
• Parameter Avg Max
• BOD5
• Ammonia
• Fecal Coliform

16
Decentralized Wastewater Treatment Concerns

• Long Term Viability of Land Application Areas
• Operation and Maintenance
• Use by Single Family Residences
• Local Government Concern for Growth Planning

17
Whats Ahead at TDEC

• Review of Design Criteria
• Revisit Allocation of Responsibilities between
  Division of Water Pollution Control and Division
  of Groundwater Protection