. Author manuscript; available in PMC: 2009 Sep 17.

Published in final edited form as: Environ Sci Technol. 2006 May 15;40(10):3168–3173. doi: 10.1021/es052426p

Table 2.

Nitrate and Total Phosphorus flux and concentration from the EISA.

River	Reference	Mean Flowrate (m³/s)	NO₃ Flux (MT/yr)	NO₃ conc. (mg/l)	Total P Flux (MT/yr)	Total P conc. (mg/l)
Cedar R. at Waterloo	This Study^a	82.5	18,851	7.23	937	0.36
Cedar R. at Waterloo	Goolsby et al.^b	122.3	18,014	4.67	887	0.23
Cedar R. near Conesville	This Study^a	140.2	30,932	7.00	2,250	0.51
Cedar R. near Conesville	Libra et al.^c	- -	37,019	NR	1,461	NR
Cedar and Iowa Combined at Wapello	This Study^a	281.5	59856	6.74	4397	0.50
Cedar and Iowa Combined at Wapello	Goolsby et al.^b	288.9	44,573	4.99	2826	0.31
Iowa R. at Columbus Jct.	This Study^a	69.6	28,924	6.74	2,147	0.50
Iowa R. at Columbus Jct.	Libra et al.^c	- -	14,175	- -	565	- -
Skunk R. at Augusta	This Study^a	107.1	22,123	6.55	3,517	1.04
	Goolsby et al.^b	92.6	17,280	4.23	1,338	0.30
	Libra et al.^c	- -	10,664	- -	540	- -
Wapsipinicon R. at De Witt	This Study^a	42.5	9,534	7.11	481	0.36
Wapsipinicon R. at De Witt	Libra et al.^c	- -	13,378	- -	460	- -
EISA TOTAL	This Study^a	- -	91,513	- -	8,395	- -
EISA TOTAL	Libra et al.^c	- -	75,236	- -	3,026	- -

This study includes data from 1996 through 2004.

Goolsby et al. includes data from 1980 through 1996. They report results for the Cedar River at Waterloo, the Cedar and Iowa Rivers combined and the Skunk River. They do not report results for the Wapsipinicon River.

Libra et al. include data from 1999 through 2001. They do not report nutrient concentrations