factors affecting water quality

 

Q: What factors contribute to the quality of a city’s drinking water?  It appears according to a recent report, 10 U.S. cities with the worst drinking water, that Florida has two cities which show up on the list (Jacksonville and Pensacola). For a peninsula, you would think the quality would be better. How does the natural Floridan aquifer affect the quality of the water (other than providing a sandy taste)?

 

A: The two biggest factors that contribute to the quality of a city’s drinking water are 1) the source of the water and 2) what treatment methods are employed before sending the water out.

Jacksonville has a lot of disinfection by-products in the water.  It’s hot there and biological contaminants will grow pretty easily in the water so the city uses disinfectants such as chlorine to reduce the growth of microorganisms.  The chlorine will react with organic matter that is present in nearly all water systems to produce disinfection by products.  According to Jacksonville’s website their water comes from a limestone aquifer so the source of water isn’t bad, they just use chlorine to keep biological contaminants out.

Pensacola has the deck stacked against them with their source water.  There the water comes from 32 sand and gravel aquifers, which many organic contaminants can easily leach through to get into the water table.  The water utility tries to clean up the water with a lot of adsorption media but it’s expensive to treat a lot of water that’s going to be used in toilets and for watering your lawn.

 

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