... Chilton, S Appleyard, H Dieter, D Wauchope and J Fastner 4.1 Chapter – p Subsurface transport and attenuation of chemicals Understanding of the transport and attenuation of chemicals in the subsurface ... texts and references therein: Schwartz and Zhang (2003), Fetter (1999), Bedient et al (1999), Domenico and Schwartz (1998), Stumm and Morgan (1996), Appelo and Postma (1993) and Freeze and Cherry ... activities such as agriculture and sanitation (see Chapters and 10) Health impacts Ammonia in drinking water is not of health relevance, and therefore WHO have not set a health- based guideline value...