THE CHEMIST (e.g. May. 2014) | Page 7

Rainwater in the storm drainage systems. Major pollutants.

Most of our rainwater travels through gutters, storm drains, channels, washes and eventually into the major source of our drinking water. The largest source of stormwater pollution in a results from every day activities.

These pollutants are picked up as water (from rain, hoses, sprinklers, etc.) drains from streets, parking lots, and lawns and enters the 66,000 catch basins throughout the city. From there the polluted urban runoff and rainwater flows through a massive system of pipes and open channels straight to the city. Basically, anything dumped or dropped on the ground or in the gutter contributes to storm water pollution.

a.Atmospheric pollutants

Persistent organic pollutants such as PCBs and the PBDEs (PolyBrominated Diphenyl Ethers), which are found in flame-retardants, water-repellent coatings and synthetic fragrances

Oxidized mercury

* Atmospheric nitrogen

b.Urban pollutants

* Oil, rubber, heavy metals, and other contaminants from automobiles.

* Garbage dumps, toxic waste and chemical storage and use areas, leaking fuel storage tanks, and intentional dumping of hazardous substances.