ENVIRONMENTAL POLLUTION ELSEVIER Environmental Pollution 121 (2003) 453-462 www.elsevier.com/locate/envpol Polyacrylamide + Al 2 (SO 4) 3 and polyacrylamide + CaO remove coliform bacteria and nutrients from swine wastewater James A. Entry", Ian Phillips b , Helen Stratton b , R.E. Sojka a 8 USDA Agricultural Research Service, Northwest Irrigation and Soils Research Laboratory, 3793 North 3600 East, Kimberly, ID, 83341, USA bSchool of Environmental Engineering, Griffith University, Nathan, Queensland, 4111, A ustralia Received 21 January 2002; accepted 16 April 2002 "Capsule": Polyacrylamide mixture may be able to reduce run-off of enteric bacteria from animal wastes. Abstract Animal wastes are a major contributor of nutrients and enteric microorganisms to surface water and ground water. Poly- acrylamide (PAM) mixtures are an effective flocculent, and we hypothesized that they would reduce transport of microorganisms in flowing water. After waste water running at 60.0 1 min' flowed over PAM + Al2(SO4)3, or PAM + Ca0 in furrows, total coliform bacteria (TC) and fecal coliform bacteria (FC) were reduced by 30-50% at 1 and 50 m downstream of the treatments compared to the control. In a column study, PAM + Al 2 (SO4 ) 3 , and PAM + Ca0 applied to sandy, sandy loam, loam, and clay soils reduced NH4 and ortho-P concentrations in leachate compared to the source waste water and the control. PAM + Al 2 (SO4) 3 and PAM + CaO applied to sandy, sandy loam and loam soils reduced both total and ortho-P, concentrations in leachate compared to the source wastewater and control treatment. In a field study, PAM + Al 2 (SO4 ) 3 , or PAM + CaO treatments did not consistently reduce NH4 , ortho-P, and total P concentrations in wastewater flowing over any soil compared to inflow wastewater or the control treatment. With proper application PAM + Al 2 (SO4) 3 and PAM + CaO may be able to reduce the numbers of enteric bac- teria in slowly flowing wastewater running off animal confinement areas, reducing the amount of pollutants entering surface water and groundwater. Published by Elsevier Science Ltd. Keywords: Runoff; Surface water; Soils; Australia; Groundwater; Pathogens 1. Introduction In Australia pollution of surface flow and ground- water from the application of animal waste has been well documented (Imbeah, 1998; Eyre and Pepperell, 1999; McKee and Eyre, 2000; Sparrow et al., 2000). Liquid-waste discharge onto soil initiates solute and microbe movement into the soil that follows natural ground water drainage patterns and may contaminate adjoining surface water. These same bodies of water are often used for sources of drinking water and/or for recreational activities. Human contact with recreational waters containing intestinal pathogens is an effective method to spread disease. Therefore, it is critical to Corresponding author. Tel.: + 1-208-423-6223; fax: +1-334-423- 6555. E-mail addresses: jentry@kimberly.ars.pn.usbr.gov (J.A. Entry), i.phillips@mailbox.gu.edu.au (I. Phillips), h.stratton@mailbox.gu . edu.au (H. Stratton), sojka@kimberly.ars.pn.usbr.gov (R.E. Sojka). 0269-7491/02/$ - see front matter Published by Elsevier Science Ltd. P11: S0269-7491(02)00225-7 maintain the quality of our lakes and streams by keeping them free of intestinal pathogens and excess nutrients. Increased N and P concentrations in water can alter the function and stability of many riparian and aquatic ecosystems. In the past few decades, intensive fertili- zation has contributed to the accumulation of these ele- ments in aquatic environments (Vitousek et al., 1997; David and Gentry, 2000; Edwards et al., 2000; Sharpley et al., 2000). Changes in flora and fauna have been attributed to increased input of nutrients (Davis, 1991; Koch and Reddy, 1992; Cooper and Brush, 1993; Ste- venson et al., 1993). Most aquatic ecosystems develop in conditions limited by N and P. Increased N and P in wetland ecosystems may also cause eutrophication, creating an abnormally high oxygen demand and often resulting in the death of many aquatic organisms (Cooper and Brush, 1993). Management practices that are currently used to mitigate the input of pollutants from animal waste to surface and groundwater include control of animal