SUMMARY OF EFFLUENT TOXICITY TESTING - THERESA ST. TREATMENT PLANT
        Percent Mortality Percent Effluent         Residual   Hardness Alkalinity Ave. Plant Upstr. Salt Effluent Instream
Sampling Agency/   Test Acute Acute Chronic 24-Hour 48-Hour 96-Hour   NOEC     LOEC     Cond.   Temp. D.O. Cl2 NH3-N as CaCO3 as CaCO3 Flow Crk. Flow Toxicity Toxicity
Period Lab Comments Organism 24-Hour 48-Hour 7-Day LC50 LC50 LC50 Survival Growth Reprod. Survival Growth Reprod. IC25 µmhos/cm pH °C mg/l mg/l mg/l mg/l mg/l cfs cfs TUc [1] TUc [2]
09/26/1988 A&L 24 Hr. Effluent Composite C. dubia 25.0%                         1,210 7.3 20.5 8.3 < 0.1 0.28     26.9 35    
to Midwest   P. promelus 0.0%                                                
09/27/1988   Grab Sample of Salt Creek Water at W. Prop. Line C. dubia 100.0%                                                
    Above Treatment Plant P. promelus 0.0%                                                
7/31/89 to EPA & No mortality at <= 50% eff. C. dubia     20.0%     70.7% 50.0%   50.0% 50.0%   50.0%   1,290 7.45-8.10 25.5-25.8 5.9-6.9 #N/A #N/A 222 189 27.2 34    
08/03/89 Univ. Wyo. Glassware Contamination P. promelus     12.5% >100% >100% >100% 100.0% #N/A                                  
07/09/1990 A&L Original Effluent Sample C. dubia 100.0%                         1,209 7.61-8.01 20-20 8.95-9.00 0.95 4.52-4.17     27.6 49    
to Midwest   P. promelus 100.0%                                                
07/10/1990   Chlorine Stripped Sample C. dubia 10.0%                         1,209 7.66-8.01 20-20 8.75-8.80 <0.5 4.52-4.17            
      P. promelus 15.0%                                                
    Ammonia Stripped Sample C. dubia 5.0%                         1,209 8.51-8.41 20-20 8.25-8.70 0.3 1.88-1.10            
      P. promelus 90.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 20.0%                         1,209 8.52-8.40 20-20 8.15-8.25 <0.5 1.88-1.10            
      P. promelus 15.0%                                                
08/18/1990 A&L Original Effluent Sample C. dubia 100.0%                         1,104 8.01-7.98 20-20 9.25-9.00 0.4 1.21-1.18     28.7 36    
to Midwest   P. promelus 50.0%                                                
08/19/1990   Ammonia Stripped Sample C. dubia 15.0%                         1,104 8.60-8.26 20-20 8.20-7.95 0.4 0.46-0.40            
      P. promelus 0.0%                                                
    Chlorine Stripped Sample C. dubia 0.0%                         1,104 7.95-7.94 20-20 9.30-8.55 0.0 1.21-1.18            
      P. promelus 0.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 10.0%                         1,104 8.61-8.24 20-20 8.20-8.20 0.0 0.46-0.40            
      P. promelus 0.0%                                                
08/19/1990 A&L Original Effluent Sample C. dubia 100.0%                         1,167 7.80-7.92 20-20 8.40-8.55 0.65 2.98-3.15     28.9 34    
to Midwest   P. promelus 100.0%                                                
08/20/1990   Ammonia Stripped Sample C. dubia 20.0%                         1,167 8.47-8.26 20-20 8.05-8.35 0.65 0.63-0.64            
      P. promelus 0.0%                                                
    Chlorine Stripped Sample C. dubia 45.0%                         1,167 7.87-7.97 20-20 8.55-8.10 0.0 2.98-3.15            
      P. promelus 0.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 5.0%                         1,167 8.52-8.22 20-20 8.25-8.15 0.0 0.63-0.64            
                                                         
08/20/1990 A&L Original Effluent Sample C. dubia 100.0%                         1,246 7.91-8.02 20-20 8.55-7.80 0.75 4.20-4.20     30.1 35    
to Midwest   P. promelus 100.0%                                                
08/21/1990   Ammonia Stripped Sample C. dubia 0.0%                         1,246 8.29-7.86 20-20 8.30-8.15 0.75 0.72-0.72            
      P. promelus 0.0%                                                
    Chlorine Stripped Sample C. dubia 0.0%                         1,246 7.83-7.91 20-20 8.30-8.40 0.0 4.20-4.20            
      P. promelus 10.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 5.0%                         1,246 8.31-7.78 20-20 8.15-8.05 0.0 0.72-0.72            
      P. promelus 0.0%                                                
04/16/1991 A&L Original Effluent Sample C. dubia 100.0%                         1,506 7.60-7.92 20-20 9.61-9.31 0.55 9.38-8.82     27.8 59    
to Midwest   P. promelus 100.0%                                                
04/17/1991   Ammonia Stripped Sample C. dubia 100.0%                         1,550 8.45-8.38 20-20 8.83-9.45 <0.5 0.98-1.19            
      P. promelus 75.0%                                                
    Chlorine Stripped Sample C. dubia 100.0%                         1,480 7.67-7.92 20-20 10.30-9.31 <0.5 9.10-9.03            
      P. promelus 50.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 0.0%                         1,550 8.47-8.28 20-20 8.79-8.40 <0.5 1.33-1.33            
      P. promelus 15.0%                                                
06/15/1992 A&L Original Effluent Sample C. dubia 100.0%                         1,087 7.57-8.05 20-20 8.68-7.10 0.3 3.36-3.50     26.6 61    
to Midwest   P. promelus 0.0%                                                
06/16/1992   Ammonia Stripped Sample C. dubia 5.0%                           7.48-7.85 20-20 7.90-6.20 0.3 1.72-1.66            
      P. promelus 0.0%                                                
    Chlorine Stripped Sample C. dubia 0.0%                           7.69-8.03 20-20 8.73-6.80 ND 4.76-3.36            
      P. promelus 0.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 0.0%                           7.43-7.90 20-20 7.85-5.40 ND 5.11-2.31            
      P. promelus 0.0%                                                
06/28/1993 A&L Original Effluent Sample C. dubia 100.0%                           8.01-8.30 24.5-22 11.30-8.21 0.55 5.73-6.05     37.0 450    
to Midwest   P. promelus 100.0%                                                
06/29/1993   Ammonia Stripped Sample C. dubia 100.0%                           8.20-8.30 24.5-22 10.41-7.81 0.55 1.21-1.16            
      P. promelus 100.0%                                                
    Chlorine Stripped Sample C. dubia 5.0%                           8.10-8.20 24.5-22 9.90-6.85 ND 1.21-NA            
      P. promelus 0.0%                                                
    Both Cl2 & NH3 Stripped C. dubia 5.0%                           8.40-8.20 24.5-22 8.48-5.13 ND 1.21-0.80            
      P. promelus 0.0%                                                
3/28/94 to A&L Disinfectant Test w/ Bromine + C. dubia 0.0%                         1,348 7.90-8.30 21.0-21.3 8.30-6.80 <0.05 8.40-7.28     26.7 129    
3/29/94 Midwest Reduced Chlorine Dose P. promelus 0.0%                                                
6/21/94 to Midwest Original Effluent Sample C. dubia 0.0%                         1,268 7.80-8.30 22.9-21.7 8.40-7.30 ND 3.81-5.04     30.0 356    
6/22/94 Lab   P. promelus 0.0%                                                
8/29/94 to EPA   C. dubia 0.0% 0.0%                       1,220 7.81-8.64 24.7-25.2 7.30-7.60 <0.02 10.6-NA 226 206 28.2 90    
8/30/94     P. promelus 0.0% 0.0%                                              
09/05/1995 EA Original Effluent Sample C. dubia 0.0%   90.0%                     182-1,190 7.7-8.2 19.3-21.0 8.5-9.1 <0.01 1.2-5.0 224-240 170-186 32.9 59    
to Sparks, MD (C. dubia = 8-day Chronic; Hardness Impairment) P. promelus 0.0%   5.0%         <12.5%     12.5%   >100% 767-1,526 8.2+-0.31 23.2-26.0 4.9-8.3             < 1.0 < 0.36
09/06/1995   Ammonia Stripped Sample C. dubia 0.0%   44.0%                                            
    (C. dubia = 8-day Chronic; Hardness Impairment) P. promelus 0.0%   5.0%                                            
11/13/1995 EA Original Effluent Sample C. dubia   20.0% 20.0%   >100%       50.0%     80.0% 68.2% 184-1900 7.8-8.7 23.4-27.0 7.3-8.6 0 17.7 236 246 30.2 62 1.47 0.48
to Sparks, MD (C. dubia = 6-day Chronic; No Chlorination) P. promelus   100.0% 100.0%   86.4% 83.6%   25.0%     50.0%   50.4% 184-1506 7.4-8.8 23.0-26.0 4.1-8.4 0           1.98 0.94
11/14/1995   Ammonia Stripped Sample C. dubia   0.0% 0.0%                                            
    (C. dubia = 6-day Chronic; No Chlorination) P. promelus   0.0% 2.0%                                            
2/5/96 to EPA C. dubia = 6-day chronic test C. dubia     30.0%       100.0% 50.0% 100.0%     100.0% 63.6% 1294-1481 7.57-8.06 24.0-24.9 4.2-7.6 0 13.1-16.0 226-264 212-300 30.2 127 1.57 0.30
2/9/96   P. promeluas = 7-day chronic test P. promelus     87.5%       12.5% 12.5%     25.0%   24.5%                     4.08 0.96
09/10/1996 EA Original Effluent Sample; CO2 Head Space C. dubia 0.0% 80.0% 100.0%   93.2%       80.0%     100.0% 62.1% 177-1557 7.5-8.6 19.8-20.6 7.3-8.6 0 13.2-21.7 216-236 232-268 33.0 184 1.61 0.24
to Sparks, MD (C. dubia = 6-day Chronic; No Chlorination) P. promelus 100.0% 100.0% 100.0%   61.9% 56.1%   25.0%     50.0%   32.2% 177-1552 7.2-8.6 24.0-25.8 4.0-8.6 0           3.11 0.55
09/16/1996   Ammonia Stripped Sample; CO2 Head Space C. dubia 0.0% 0.0% 0.0%                                            
    (C. dubia = 6-day Chronic; No Chlorination) P. promelus 0.0% 7.0% 7.0%                                            
03/04/1997 EA Original Effluent Sample C. dubia 0.0% 0.0% 100.0%   > 100%       50.0%     80.0% 89.7% 175-2030 7.8-8.2 19.8-21.0 8.4-8.9 <0.01 1.98-5.63 220-232 166-190 26.9 273 1.11 0.10
to Sparks, MD (C. dubia = 6-day Chronic; No Chlorination) P. promelus 15.0%                         203-2200 7.9-8.4 19.1-21.0 8.5-9.2                
03/10/1997   Ammonia Stripped Sample C. dubia 0.0% 0.0% 100.0%                                            
    (C. dubia = 6-day Chronic; No Chlorination) P. promelus 10.0%                                                
04/01/1997 EA Original Effluent Sample (No Chlorination)                                                    
to Sparks, MD 0 ppt Salinity P. promelus   2.0% 27.0%     > 100%   100.0%     > 100%   88.4%   7.6-8.2 24.0-25.7 6.9-8.3 <0.01 3.20-5.28 220-240 180-186 26.6 136 1.13 0.19
04/07/1997   1 ppt Salinity P. promelus   5.0% 7.0%     > 100%   100.0%     > 100%   > 100%                     < 1.0 < 0.16
    2 ppt Salinity P. promelus   12.0% 22.0%     > 100%   100.0%     > 100%   > 100%                     < 1.0 < 0.16
     4 ppt Salinity P. promelus   11.0% 17.0%     > 100%   100.0%     > 100%   > 100%                     < 1.0 < 0.16
    Ammonia Stripped Sample P. promelus   0.0% 0.0%                                            
08/23/1998 EA Original Effluent Sample C. dubia 0.0% 0.0% 12.0%   > 100% #N/A     100.0%     > 100% 91.3% 1,094-1,294 6.9-7.5 23.9-26.1 5.4-10.5 < 0.01 4.32-14.7 240-268 208-252 39.7 161 1.10 0.22
to Sparks, MD (Time of Flow Diversion from NETP) P. promelus 0.0% 0.0% 10.0%   > 100% > 100%   80.0%     100.0%   94.0%                     1.06 0.21
08/28/1998   Ammonia Stripped Sample C. dubia 0.0% 10.0% 20.0%   > 100% #N/A     100.0%     > 100% > 100%                     < 1.0 < 0.20
    (C. dubia = 8-day Chronic) P. promelus 0.0% 25.0% 57.0%   > 100% 100.0%   80.0%     100.0%   80.8%                     1.24 0.24
    Ammonia Add-Back to Orig. Conc. C. dubia 5.0% 0.0% 90.0%   > 100% #N/A    < 80%       80.0% 23.8%                     4.20 0.83
    (C. dubia = 8-day Chronic) P. promelus 0.0% 2.0% 82.0%   > 100% 93.9%     < 80%   80.0%   50.9%                     1.96 0.39
02/23/1999 EA Original Effluent Sample C. dubia 30.0% 40.0% 90.0% > 100%  > 100% 93.2%     25.0%     50.0% 39.4% 1,322-1,637 7.4-7.5 21.5-25.9 4.9-8.4 < 0.01 17.1-38.8 240-244 234-310 27.7 175 2.54 0.35
to Sparks, MD (C. dubia = 6-day Chronic) P. promelus 95.0% 100.0% 100.0% 72.3% 61.2% 58.9%   50.0%     80.0%   51.7%                     1.93 0.26
03/01/1999   Ammonia Stripped Sample C. dubia 5.0% 0.0% 0.0% > 100%  >100%  >100%     80.0%     100.0% > 100%                     < 1.0 < 0.14
    (C. dubia = 6-day Chronic) P. promelus 0.0% 0.0% 7.0% > 100%  >100%  >100%   100.0%      >100%   > 100%                     < 1.0 < 0.14
    Ammonia Add-Back to Orig. Conc. C. dubia 65.0% 90.0% 100.0% 80.0% 80.0% < 80%      < 80%     80.0%  < 80%                     > 1.25 > 0.17
    (C. dubia = 6-day Chronic) P. promelus 100.0% 100.0% 100.0% < 80% < 80% < 80%   < 80%     80.0%   < 80%                     > 1.25 > 0.17
09/26/1999 EA Original Effluent Sample C. dubia 100.0% 100.0% 100.0% 37.0% 35.4% 35.4%   25.0%     50.0%   31.3% 1,206-1,478 7.3-8.7 19.6-26.0 8.4-9.0 <0.01-0.09 25.0-41.2 232-240 262-326 25.5 115.4 3.19 0.58
to Sparks, MD   P. promelus 100.0% 100.0% 100.0% 49.2% 58.6% 48.4%   25.0%     50.0%   30.7%                     3.26 0.59
10/01/1999   Ammonia Stripped Sample C. dubia 100.0% 30.0% 40.0% <80% >100% >100%   80.0%     100.0%   86.8%                     1.15 0.21
      P. promelus 5.0% 0.0% 0.0% >100% >100% >100%   100.0%     >100%   >100%                     < 1.0 < 0.18
    Ammonia Add-Back to Orig. Conc. C. dubia 100.0% 100.0% 100.0% <80% <80% <80%   <80%     80.0%   <80%                     > 1.25 > 0.23
      P. promelus 100.0% 100.0% 100.0% <80% <80% <80%   <80%     80.0%   <80%                     > 1.25 > 0.23
10/10/1999 EA Original Effluent Sample C. dubia 0.0% 0.0% 100.0% >100% >100% 75.4%   25.0%     50.0%   33.1% 1,258-1,558 7.6-8.8 19.6-26.2 5.9-8.8 <0.01-0.05 16.3-29.2 224-236 106-264 26.5 43.4 3.02 1.15
to Sparks, MD (C. dubia = 8-day Chronic) P. promelus 100.0% 100.0% 100.0% 59.0% 50.0% 41.6%   12.5%     25.0%   31.2%                     3.21 1.22
10/18/1999   Ammonia Stripped Sample C. dubia 0.0% 0.0% 90.0% >100% >100% >100%   <80%     80.0%   >100%                     < 1.0 < 0.38
    (C. dubia = 6-day Chronic) P. promelus 0.0% 0.0% 0.0% >100% >100% >100%   100.0%     >100%   >100%                     < 1.0 < 0.38
    Ammonia Add-Back to Orig. Conc. C. dubia 100.0% 90.0% 100.0% <80% <80% <80%   <80%     80.0%   <80%                     > 1.25 > 0.47
    (C. dubia = 6-day Chronic) P. promelus 100.0% 100.0% 100.0% <80% <80% <80%   <80%     80.0%   <80%                     > 1.25 > 0.47
File:  F:\MSExcel\San\Sampling\SurfaceWQ\ToxSum.xls      
     
  [1]   Effluent TUc was calculated as the reciprocal of the IC25 effluent toxicity concentration and is relative to plant effluent end of pipe.        
  [2]  Instream TUc was calculated as the Effluent TUc x (Qe/(Qe + Qs)), where Qe = plant effluent flow and Qs = upstream flow in Salt Creek.        
  NDEQ Proposed Limits:      
  Theresa St. Plant:  7Q10 summer = 13.7 cfs and TUc = 2.46 max. based on NOEC; 7Q10 winter = 21.7 cfs and TUc = 2.55 max based on NOEC.      
  Northeast Plant:  7Q10 summer = 43 cfs and TUc = 1.8 max. based on NOEC; 7Q10 winter = 50 cfs and TUc = 1.8 max based on NOEC.      
  In general, TUc shall not exceed 1.0 at the end of the chronic mixing zone; the City is allowed 100% mixing allowance with Salt Creek flow.