The runoff causes sediment transport in surface waters. It contains residue from animal lots, and P, N, trace metals, and organics from fertilizers, pesticides, and herbicides. Agriculture is the biggest single user of water - used mainly for irrigation. These are listed in Table 15.5. These arise from the use of commercial and agricultural fertilizers, and from other products.
Solvents are toxic, and cause stratospheric ozone depletion and smog formation.
Flow analysis conducted. Surface-coating reformulated to one requiring less solvent for removal. Rather than use toluene, which required residue incineration, changed to solvent that could be recovered by distillation. Strong mineral acids used as processing chemicals. Acids generated through mining are more difficult to control than the acids used in product manufacturing.