Table 12. Percent removal of dissolved organic carbon and disinfection by-product formation precursors during treatability jar-test experiments conducted at the Clackamas River Water drinking-water treatment plant, Clackamas River basin, Oregon, 2010–11.


[Average values ± one standard devation. Removal of dissolved organic carbon (DOC) from source to finished water is shown for comparison. Abbreviations: DBP, disinfection by-product; THMs, trihalomethanes; HAAs, haloacetic acids; PAC, powdered activated carbon; –, not applicable or no data]


Date	Treatment	Percent removal
		DOC			DBP precursors
					THMs			HAAs
05-12-10	Coagulation	36		–	42	±	5.3	76	±	1.6
	Coagulation + PAC	40	±	5.7	52	±	5.4	79	±	1.2
	Source-finished water1	28		–	–		–	–		–
10-10-10	Coagulation	39	±	0.0	45	±	1.8	69		–
	Coagulation + PAC	48	±	4.3	53	±	1.1	76	±	2.2
	Source-finished water1	33		–	–		–	–		–
09-09-11	Coagulation	33	±	0.0	13	±	2.9	69	±	1.4
	Coagulation + PAC	33	±	0.0	15	±	10.0	74	±	5.4
	Source-finished water1	0		–	–		–	–		–
09-22-11	Coagulation	30	±	0.0	27		–	65		–
	Coagulation + PAC	40	±	0.0	38	±	4.1	73	±	1.0
	Source-finished water1	20		–	–		–		–	–

¹Percent reductions in DOC during actual treatment at the Clackamas River Water drinking-water treatment plant.

First posted February 11, 2013