58^f 



1 1 6 WATER QUALITY CRITERIA 



TABLE 3 — Gallons of diUaioii waler needed per day lo reduce the waste streams 

 toxicities to and 20 per cent response levels. 



Bioassay Dilution Present Waste Million Gallons Per Day 



Sample N"o. Volume, million Required for 



response 20% response Gallons per day ^ ^^^^^^ ^^^^ ^^I^^^ 



44 > 20 000 19 000 2.74 > 54 800 52 060 



63 100 000 11500 13.15 1315 000 151225 



71 100 000 »7 9t)0 



70 100 000 7 800 4.50 450 000 35100 



43 10 000 4 540 29.09 290 900 130 680 



66 100 000 3 400 5 67 567 000 192 780 



39 10 000 2 100 4.60 46 000 9 660 



48 2 000 920 13.20 26 400 12 144 



73 1 000 700 



67 2 000 690 8.00 16 000 5 520 



47 1000 620 17.30 17 300 10 726 



77 2 000 560 2.92 5 840 1635 



72 100 000 550 7.80 780 000 42 900 



40 > 100 000 525 0.70 > 70 000 367 



64 1000 170 40.32 40 320 6 854 



42 2 000 145 9.00 18 000 1305 



45 1 000 72 1.13 1 130 81 



68 10 000 68 



69 200 65 5.00 1000 325 



78 200 62 0.91 182 56 



41 100 61 0.70 70 43 



76 1000 59 5.90 5 900 348 



79 100 59 1.34 134 79 



46 100 22 1.43 143 31 



75 100 18 



62 20 <10 3.49 69.8 <35 



65 <10 <10 8.40 <84 <84 



74 20 <10 



80 100 <10 



Totals 187.29 3 706 273 654 038 



larvae are counted in each sample. The response which forms the basis 

 of the bioassay is the per cent abnormal larvae. The effect of any varia- 

 ble tested is described in terms of the per cent oyster larvae which de- 

 velop abnormally. 



Results 



In a study comparing the toxicity of 29 composite wastes serial dilu- 

 tions of one part waste sample to 10, 20, 100, 200, 1000, 2000, 10,000, 

 20,000, 100,000, and 200,000 parts of fresh seawater were prepared. 

 Each dilution was divided between three one-liter beakers for replication 

 of the bioassay. At least nine beakers were filled with pure .seawater to 

 be used as controls in each of the nine separate bioassays made during 

 the study. The mean per cent abnormal larvae from each dilution of each 

 waste bioassayed was plotted on probability paper, and levels of no 



