USGS Scientific Investigations Report 2013–5001  - Sources and Characteristics of Organic Matter in the Clackamas River, Oregon, Related to the Formation of Disinfection By-Products in Treated Drinking Water 

Table 10. Percentage of dissolved organic carbon, total particulate carbon, and disinfection by-product formation potentials for individual sites relative to instantaneous loads at the Clackamas River Water drinking-water treatment plant intake during basin-wide sampling events, Clackamas River basin, Oregon. 

[Sampling site locations are shown in figure 1. Streamflow in cubic feet per second. Abbreviations: DWTP, drinking-water treatment plant; DOC, dissolved organic carbon; TPC, total particulate carbon; THM, trihalomethane; HAA, haloacetic acid; FP, formation potential; F, filtered; U, unfiltered; –, no data] 

Sampling site	River mile	Date	Streamflow	Percent of load at the Clackamas River Water DWTP intake
Sampling site	River mile	Date	Streamflow	DOC	TPC	THMFP-F	THMFP-U	HAAFP-F	HAAFP-U
May 11–13, 2010 (Spring high flow)
Clackamas River at Carter Bridge	40.8	05-11-10	2,665	67	54	55	61	71	99
Clackamas River at Estacada	23.1	05-11-10	3,579	91	57	81	77	117	121
Eagle Creek	16.7	05-11-10	422	12	10	10	10	13	18
Clackamas River at Barton Bridge	13.4	05-12-10	3,700	94	78	121	99	78	99
Deep Creek	12.1	05-11-10	58	2.4	2.2	1.7	1.5	3.2	3.0
Clear Creek	8	05-11-10	162	4.4	6.1	3.8	3.7	5.2	6.9
Clackamas River at Carver	7.9	05-12-10	3,760	95	104	103	107	108	101
Rock Creek	6.4	05-11-10	4.6	0.2	0.05	0.16	0.14	0.24	0.26
Sieben Creek	5.8	05-11-10	0.8	0.04	0.01	0.03	0.03	0.05	0.05
CRW DWTP–Source water	3.1	05-12-10	3,646	100	100	100	100	100	100
LO DWTP–Source water	0.9	05-13-10	3,549	–	–	–	–	–	–
October 10, 2010 (“Initial” autumn storm event)
Clackamas River at Carter Bridge	40.8	10-10-10	938	45	22	52	41	56	38
Clackamas River at Estacada	23.1	10-10-10	1,338	54	22	52	45	47	31
Eagle Creek	16.7	10-10-10	197	28	16	33	28	57	37
Clackamas River at Barton Bridge	13.4	10-10-10	1,535	68	39	65	62	77	47
Deep Creek	12.1	10-10-10	167	49	70	42	56	108	65
Clear Creek	8	10-10-10	60	9	3.2	8.6	8	19	10
Clackamas River at Carver	7.9	10-10-10	1,650	113	114	109	105	127	95
Rock Creek	6.4	10-10-10	29	9	8	7.3	8.1	16	9.5
Sieben Creek	5.8	10-10-10	21	4.5	3.5	4.0	4.0	7.9	4.5
CRW DWTP–Source water	3.1	10-10-10	1,548	100	100	100	100	100	100
LO DWTP–Source water	0.9	10-10-10	1,639	112	58	109	101	104	85
September 8–9, 2011 (Summer base flow)
Clackamas River at Carter Bridge	40.8	09-08-11	811	73	38	76	50	68	138
Clackamas River at Estacada	23.1	09-09-11	957	98	76	119	82	88	138
Eagle Creek	16.7	09-08-11	25	4	2	4	3	6	6
Clackamas River at Barton Bridge	13.4	09-09-11	980	101	148	113	140	98	134
Deep Creek	12.1	09-08-11	9	2.0	1.2	1.7	1.3	3.3	3.4
Clear Creek	8	09-08-11	18	3.4	1.5	3.0	2.4	7.1	6.8
Clackamas River at Carver	7.9	09-09-11	1,000	103	78	137	92	94	105
Rock Creek	6.4	09-08-11	1.0	0.2	0.05	0.13	0.12	0.18	0.17
Sieben Creek	5.8	09-08-11	0.2	0.0	0.14	0.04	0.03	0.05	0.07
CRW DWTP–Source water	3.1	09-09-11	864	100	100	100	100	100	100
LO DWTP–Source water	0.9	09-09-11	897	115	123	116	92	102	121
September 22, 2011 (Timothy Lake drawdown)
Clackamas River at Two Rivers campground	57	09-16-11	343	22	30	13	10	17	10
Clackamas River at Carter Bridge	40.8	09-16-11	858	64	79	46	34	57	33
Clackamas River at Estacada	23.1	09-22-11	943	103	92	87	66	79	44
Clackamas River at Barton Bridge	13.4	09-22-11	969	95	115	104	112	84	71
Clackamas River at Carver	7.9	09-22-11	994	80	97	86	109	96	53
CRW DWTP–Source water	3.1	09-22-11	944	100	100	100	100	100	100
LO DWTP–Source water	0.9	09-22-11	930	89	88	96	101	109	52