On Site Systems. Capacity Allocation Model for Permitting and County Comprehensive Plans. Maryland Ground Water Symposium September 25, 2008

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1 Maryland Ground Water Symposium September 25, 2008 On Site Systems Capacity Allocation Model for Permitting and County Comprehensive Plans Craig Goodwin NCS Wastewater Solutions Anish Jantrania Virginia Dept. of Health

2 Nitrogen Input to the Bay Manure 18% Fertilizer 26% POTWs 19% Input from Wastewater ~ 23% Septic 4% Emission 33% Reference:

3 Nitrogen Input from Wastewater Septic Systems and Sewage Treatment When development occurs in existing urban and suburban areas, wastewater generated by new residents is typically treated by a public wastewater treatment plant. But when new homes are built far from public infrastructure, their wastewater is usually treated by on-site septic systems. Discharges from septic systems depend on a variety of technological and geographic factors; however, on average: Municipal wastewater treatment plants annually deliver about 3.1 pounds of nitrogen per person to the Bay and its rivers. Septic systems annually deliver about 9.5 pounds of nitrogen per person.

4 QUESTIONS Should there be any difference between the standards for nitrogen loading from municipal treatment plants and the standards for nitrogen loading from onsite systems? NO Can the nitrogen loading from septic systems (onsite systems) be no more than that from the municipal treatment plant (3.1 lb/person/year)? YES

5 Anne Arundel County Study Conclusions

6 Why Decentralized Sewer 1. Improved Land Use 2. Density Matched to Zoning 3. Efficient Treatment & Nutrient Reduction 4. Community Asset

7 Individual Home Septic Systems

8 Decentralized Sewer

9 Nutrient Reduction Efficiency The Legacy Howard County MD SBR Treatment Plant Drip in Trench Dispersal < 8 TN Monitoring Wells Monthly DMR s

10 Nutrient Reduction Efficiency St. John s School Frederick County, MD SBR Treatment Plant Drip Dispersal < 8 TN Treatment 0 TN in Percolate Monitoring Wells Monthly DMR s

11 Wastewater Reclamation & Reuse The Future in Maryland? Existing WWTP Existing Septic 2,820 lbs N Cap 470 lbs P Cap 250 Residences New Reuse Plant Coal Fired Power Plant 4 million gpd Cooling Tower New Subdivision $$$$ Nutrient Trade 2,820 lbs N 470 lbs P 1,000 Residences

12 MOWPA August 25, 2008 Shared Facilities Status in Maryland Biggest Roadblocks 1. Controlling Authority Required 2. County Comprehensive Plans for Water & Sewer

13 Private Utilities Filling the Void Professional Management Charging Market Rates Maintenance Bond Security - 3 Years Operating Costs - Allowance for Equipment Replacement

14 Typical Zoning Profile Zoned by Septic

15 Zoned by Septic Zoned by Septic

16 Capacity Allocation Model Regulatory Approach for OS Similar to Surface Discharge Permits Hydraulic and TMDL Capacity Allocation to the Land by Rule Based on Treatment and Management; Performance Based Design by P.E. for the Capacity Allocated to the Project Area; Installation and Operation by Licensed Professionals; Mandatory Monitoring of Compliance Standards; and Financial Consequences for Out of Compliance Operation.

17 Using Land for Effluent Dispersal Regulations Foundation Regulations Based On: Drain Field Location & Sizing Prescriptive Designs versus Project Area Performance Designs

18 Drain Field Location & Size Approach to Capacity Allocation X GPD STE or Perc Rate < 120 mpi Depth > 3 ft Meet other requirements Capacity Allocation = X GPD of STE or for A Acres

19 Drain Field Location & Size Approach to Capacity Allocation Capacity Allocation = X GPD of STE or for A Acres Hydraulic Conductivity Depth to Limitations Topography Pollution Load Organic Bacteriological Nutrient - F A TB P

20 Project Area & Performance Approach to Capacity Allocation Capacity Allocation = X1-12 GPD of TL-1, 2, 3 or 4 & MM-A, B, or C for A Acres

21 Project Area & Performance Approach to Capacity Allocation

22 Project Area & Performance Approach to Capacity Allocation Are we meeting the Environmental Quality Standards? Are we meeting the Public Health Standards?

23 New Ideas / Concepts Capacity of land to assimilate effluent can be expressed as inch/year and described as FlowArea-Index, FAI; GPD X Formula#1: FAI inch/year = Acres Where GPD = Quantity of Effluent Acres = Project Area NOT the Drain Field Area

24 Mass Loading - TMYL For effluent dispersed on land, mass loading of regulated pollutants could be expressed as lb/yearacre ; If limits for pollutants loads are set in terms of lb/year-acre then a designer can choose between treatment and land area; Formula#2: lb/year-acre = (mg/l) X (FAI) X

25 Onsite Treatment Levels Level 1 Septic Tank (Primary Treatment) Level 2 Secondary Treatment (30/30) Level 3 Disinfection (10/10 & UV) Level 4 Nutrient Reduction (Tertiary)

26 Onsite Management Models Model A System Owner Model B Private (Non-Government) Utility Model C Public (Government) Utility

27 Capacity Allocation Matrix (FAI) by Rule Management Model Treatment Level 1 Primary Only (Septic Tank) 2 Secondary Typical 30/30 3=2+ Disinfection 4 = 3+ or 3+ Nutrient Reduction A B C Management by System Owner Management by Non-Government Utility Management by Government Utility

28 What should be the numbers? Commonsense rule - Lesser treatment, poorer effluent quality, weaker management model means lesser capacity allocation; Environmental issues mass loading and concentration of regulated pollutants going to groundwater and surface water within limits; Economical issues long term management affordable based on density allowed by the capacity allocation and technology required.

29 Capacity Allocation Matrix (FAI) by Rule Management Model Treatment Level 1 Primary Only (Septic Tank) 2 Secondary Typical 30/30 3=2+ Disinfection 4 = 3+ or 3 + Nutrient Reduction A B C Management by System Owner Management by Non-Government Utility Management by Government Utility >6.0

30 TMYL Capacity For Land Allowable Mass Loading (lb/year-acre) Set By Rule Max BOD5 200 TSS 200 Oil and Grease 200 TKN as N 10 Total P as P 10

31 Capacity Allocation Matrix (FAI) by Rule Management Model Treatment Level A B C Management by System Owner Management by Non-Government Utility Management by Government Utility 1 Primary Only (Septic Tank) 2 Secondary Typical 30/30 3=2+ Disinfection 4 = 3+ or 3+ Nutrient Reduction Start Here

32 TMYL Capacity For Land Allowable Mass Loading (lb/year-acre) Set By Rule Max BOD5 TSS Oil and Grease TKN as N Total P as P

33 New Regulations 12 Types of Onsite System Permits Management Model Treatment Level 1 Primary Only (Septic Tank) 2 Secondary Typical 30/30 3=2+ Disinfection 4 = 3+ or 3 + Nutrient Reduction A B C Management by System Owner Management by Non-Government Utility Management by Government Utility A1 B1 C1 A2 B2 C2 A3 B3 C3 A4 B4 C4

34 Case Study / Example 107 Lots, 3 BdRm Homes 127 Acres; 24 Acres Wetland; 38,520 GPD Demand

35 How to do the math? Use Spreadsheet FAI, TS, Nitrogen. Case Study / Example Answer GPD permitted for a given Project Area Input Project Area P.A. = 103 OR Acre(s) GPD Permitted: Management Model Proposed Treatmetn Levels A B C TS1 (Septic Tank) TS2 (Secondary) TS3 (Secondary + Disinfection) >45985 TS4 (TS3 + Nutrient Reduction) Values are Rounded UpTo Nearest 5 GPD YES You can get 107 Lots! Need Permit Type B4 Find a RME

36 Performance Requirements for All Systems Meet the clients expectations Customer Satisfaction; Protect the Public Health Minimize or Eliminate Direct Contact to Waste Material; Protect the Environmental Quality Meet the Discharge Limits at the Compliance Boundary.

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39 Impact on living conditions.

40 Impact on Wastewater Management Systems.

41 Maryland Ground Water Symposium September 25, 2008 Questions