Omni Environmental Raritan River Basin TMDL Study: Water Quality Targets and Future Simulations December 17, 2007 Presented to: Raritan Basin Watershed Alliance Technical Advisory Committee Presented by: Jim Cosgrove and Tom Amidon Omni Environmental LLC
Omni Environmental Purpose and Agenda � Purpose � Review water quality targets and future simulations � Agenda � Overview � Water Quality Targets � Orthophosphorus as effluent limit � What will the TMDL achieve? � Snapshots by watershed area � Discussion
Omni Environmental Overview � Raritan River Basin TMDL Study � Provide technical basis for NJDEP to develop TMDLs as necessary to address phosphorus and other conventional impairments in the Raritan River Basin � Extensive Monitoring Performed in 2004 and 2005 � Data Summary � December 19, 2005 Report � August 20, 2007 Presentation � State-of-the-Art Watershed Models Developed � Model Calibration and Validation � September 17, 2007 Presentation � Future Simulations (What would happen if …?) � Today’s Presentation
Omni Environmental Raritan Watershed Models Tidal River Raritan Bay Raritan River Basin
Omni Environmental Why are We Picking on Phosphorus? � Phosphorus is a nutrient that can stimulate excessive growth of plants and algae � Impact to dissolved oxygen (DO) � Large diurnal DO swings during summer low-flow periods � Violations of minimum DO criteria during summer nights � Impact to pH due to photosynthesis � Large diurnal pH swings during summer low-flow periods � Violations of maximum pH criteria during summer days � Excessive plants and algae � Phosphorus is causing these impacts in many waters in the Raritan River basin (“rendering unsuitable”)
Omni Environmental Regulatory Thresholds � Low Dissolved Oxygen (DO) minimums � 4 mg/l for Non-Trout Waters � 5 mg/l for Trout Maintenance Waters � 7 mg/l for Trout Production Waters � pH Criteria � 6.5 minimum to 8.5 maximum (s.u.) � Lake criterion of 0.05 mg/l TP � Stream criterion of 0.1 mg/l TP � Unless not “rendering unsuitable” for designated uses
Omni Environmental Assessing Impacts to pH � WASP simulates DO, but not pH � Photosynthesis pumps DO into the water column and utilizes CO 2 , which increases pH � High productivity results in diurnal swings of DO and pH � Site-specific correlations of pH with DO during summer � DO threshold based on the DO associated with pH of 8.5 � Average DO threshold = 12 mg/l
Omni Environmental Relationship Between DO and pH Dissolved Oxygen and pH (SBRR10) 16 r² = 0.64 Max DO based on pH of 8.5 is 10.8 mg/l 14 DO (mg/l) or pH (s.u.) 12 10 8 6 4 07/28/05 07/30/05 08/01/05 08/03/05 08/05/05 08/07/05 08/09/05 Measured pH DO Predicted pH Max pH Criterion
Omni Environmental Impacts of Point and Nonpoint Source Phosphorus Reductions � Nonpoint source reductions � Percent reduction of phosphorus in stormwater runoff from urban and agricultural areas � Point source reductions � Dissolved orthophosphorus � Organic phosphorus � Implications for wastewater treatment and regulation
Omni Environmental Impact of NPS Reduction on TP South Branch Raritan River at Solitude Lake Total Phosphorus 0.14 0.12 0.1 Concentration (mg/l) 0.08 0.06 0.04 0.02 0 6/1/2002 6/21/2002 7/11/2002 7/31/2002 8/20/2002 9/9/2002 9/29/2002 [NSB_hyd_N20P0 N20P005 N60P005 N80P005 (MRC) 0.05 mg/l criterion 05.xls]TP
Omni Environmental Impact of NPS Reduction on DO Neshanic River at Reaville Rd. near Reaville (NR1) Neshanic River at Reaville Rd. near Reaville (NR1) Neshanic River at Reaville Rd. near Reaville (NR1) Neshanic River at Reaville Rd. near Reaville (NR1) 20 20 20 20 18 18 18 18 16 16 16 16 14 14 14 14 Concentration (mg/l) Concentration (mg/l) Concentration (mg/l) Concentration (mg/l) 12 12 12 12 10 10 10 10 8 8 8 8 6 6 6 6 4 4 4 4 2 2 2 2 0 0 0 0 7/1/2002 7/1/2002 7/1/2002 7/1/2002 7/11/2002 7/11/2002 7/11/2002 7/11/2002 7/21/2002 7/21/2002 7/21/2002 7/21/2002 7/31/2002 7/31/2002 7/31/2002 7/31/2002 8/10/2002 8/10/2002 8/10/2002 8/10/2002 8/20/2002 8/20/2002 8/20/2002 8/20/2002 8/30/2002 8/30/2002 8/30/2002 8/30/2002 9/9/2002 9/9/2002 9/9/2002 9/9/2002 9/19/2002 9/19/2002 9/19/2002 9/19/2002 9/29/2002 9/29/2002 9/29/2002 9/29/2002 [NSB_hyd_N20P00 [NSB_hyd_N20P00 [NSB_hyd_N20P00 [NSB_hyd_N20P00 0% Reduction 0% Reduction 20% NPS Reduction 0% Reduction 20% NPS Reduction 0% Reduction 20% NPS Reduction 60% NPS Reduction 60% NPS Reduction 80% NPS Reduction 5.xls]DO 5.xls]DO 5.xls]DO 5.xls]DO
Omni Environmental Impact of Point Source Reductions of OrthoP vs OrgP on DO South Branch Raritan River at Studdiford Dr. in South Branch (SBRR10) South Branch Raritan River at Studdiford Dr. in South Branch (SBRR10) South Branch Raritan River at Studdiford Dr. in South Branch (SBRR10) 18 18 18 16 16 16 14 14 14 DO Concentration (mg/l) DO Concentration (mg/l) DO Concentration (mg/l) 12 12 12 10 10 10 8 8 8 6 6 6 4 4 4 2 2 2 0 0 0 8/1/2002 8/1/2002 8/1/2002 8/6/2002 8/6/2002 8/6/2002 8/11/2002 8/11/2002 8/11/2002 8/16/2002 8/16/2002 8/16/2002 8/21/2002 8/21/2002 8/21/2002 8/26/2002 8/26/2002 8/26/2002 [NSB_hy [NSB_hy [NSB_hy Existing MRC (OrthoP = 0.025 mg/l ; OrgP = 0.025 mg/l) Existing MRC (OrthoP = 0.025 mg/l ; OrgP = 0.025 mg/l) Existing MRC* (OrthoP = 0.025 mg/l ; OrgP = 1.0 mg/l) d Calibr d Calibr d Calibr
Omni Environmental Wastewater Treatment Implications � Typical secondary effluent (no P removal) � Most phosphorus is soluble orthophosphate Phosphorus Removal Steps � � Convert orthophosphorus to TSS Chemical precipitation � Secondary environmental impacts (sludge production and TDS) � Biological phosphorus removal (BPR) � Concentrates P in TSS (~6% instead of ~2%) � � Remove TSS TP Limit creates major disincentive for BPR � � BPR concentrates P in TSS by a factor 3 TSS effluent concentrations must be 3× lower to achieve the same effluent TP concentration � � To satisfy effluent TP limit of 0.1 mg/l TSS must be < 4 mg/L for non-BPR system with P content of 2% of TSS � TSS must be < 1.3 mg/L for BPR system with P content of 6% of TSS �
Omni Environmental Implications for Wastewater Regulation � What if effluent limits were expressed as Dissolved Reactive Phosphorus (Ortho P)? � OrthoP limits would be established as necessary to satisfy low DO and high pH thresholds � OrgP levels would depend on TSS concentration and whether BPR was utilized For TSS limit of 15 mg/l, OrgP would not exceed: � 0.3 mg/l without BPR � 0.9 mg/l with BPR � � TP limits may still be necessary to satisfy lake criterion (0.05 mg/l) and instream 0.1 criterion Environmental Benefits � � Targeting OrthoP targets the real productivity culprit � Eliminates disincentive for BPR BPR eliminates or reduces chemical addition �
Omni Environmental What will the TMDL Achieve? � Existing Condition � Calibrated Model � MRC (Most Reduced Condition) � 80% NPS reduction � Permitted PS flow at 0.05 mg/l (0.025 mg/l OrthoP) � Scenario 1 � 60% NPS reduction � Permitted PS flows � Effluent P concentrations vary by location to achieve water quality targets � P concentrations ranging from 0.1 to 0.5 depending on size and location � Very small dischargers left at existing effluent quality � Some locations do not require reductions of point sources � Dischargers set to long-term average associated with existing effluent limit � Other scenarios have been and will be considered
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Omni Environmental Dissolved Oxygen South Branch Raritan River at Mill Rd. in Middle Valley (SBR4) South Branch Raritan River at Mill Rd. in Middle Valley (SBR4) South Branch Raritan River at Mill Rd. in Middle Valley (SBR4) 20 20 20 18 18 18 16 16 16 14 14 14 Concentration (mg/l) Concentration (mg/l) Concentration (mg/l) 12 12 12 10 10 10 8 8 8 6 6 6 4 4 4 2 2 2 0 0 0 7/1/2002 7/1/2002 7/1/2002 7/11/2002 7/11/2002 7/11/2002 7/21/2002 7/21/2002 7/21/2002 7/31/2002 7/31/2002 7/31/2002 8/10/2002 8/10/2002 8/10/2002 8/20/2002 8/20/2002 8/20/2002 8/30/2002 8/30/2002 8/30/2002 9/9/2002 9/9/2002 9/9/2002 9/19/2002 9/19/2002 9/19/2002 9/29/2002 9/29/2002 9/29/2002 [NSB_hy [NSB_hy [NSB_hy Existing Existing Scenario 1 Existing Scenario 1 MRC d Calibr d Calibr d Calibr
Omni Environmental Total Phosphorus South Branch Raritan River at Solitude Lake (SBRR3) 0.16 0.14 0.12 Concentration (mg/l) 0.1 0.08 0.06 0.04 0.02 0 1/1/2002 2/20/2002 4/11/2002 5/31/2002 7/20/2002 9/8/2002 10/28/2002 12/17/2002 [NSB_hyd_Calibrat Existing Scenario 1 MRC ed 09182007.xls]T
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