Water Treatment and Conservation

Water Treatment Removing harmful organisms and substances from water to make it usable for human consumption and use.

Pollution Prevention By Landscape

Sewage Treatment Primary Sewage Treatment: a mechanical process that uses screens to filter out debris such as sticks, stones, and rags; suspended solids settle out as sludge in a settling tank This takes out 30 -50 % of the solids. Fatty and oily materials are skimmed off the top. This is called Raw Sludge. The water then flows out.

Secondary Sewage Treatment Biological process in which aerobic bacteria are used to remove up to 90% of biodegradable, oxygen demanding organic wastes After primary treatment, trickling filters are used and the water is aerated.

Chemical: chemicals (Aluminum Sulfate or Ferric Chloride – Iron (III) Chloride) are added to the water to precipitate the phosphorus to form a solid which is collected as sludge The activated sludge is fed into holders that ferment the sludge producing ammonia and methane which are burned in generators to make electricity for the plant. The remaining water is treated with chlorine. 90 - 95 % of the sewage is removed. Most treatment plants in USA are secondary.

Advanced (Tertiary) Sewage Treatment: a series of specialized chemical and physical processes that remove specific pollutants left in the water after primary and secondary treatment: types of advanced treatment vary according to the specific contaminants being removed The water can be heavily aerated and further treated by passing through filters to make the water drinkable, exposed to UV light or chlorine.

The Leftovers: Sludge - a black, foul smelling thick mixture of 2% solids and fats. pumped into landfills, rivers and harbors of USA can be dried and made into fertilizer (melorganite) The islands off Staten Island that everyone sails to and has their picnics on are made of sludge. Grass grows quickly on the islands and very few people are aware of what they are made of

Wastewater Treatment #1 Primary Treatment – the Muffin Monster Tertiary Water Treatment and Sludge Processing – jump to 1:00 mark Acid Mine Drainage Treatment – Chemical Free Acid Mine Drainage Chemical Treatment Dirty Jobs – Pump Cleaning – Start at 29:00

Drinking Water Quality Many rivers in eastern Europe, Latin America, and Asia are used as sources of drinking water but are contaminated with pesticides, fertilizers and hazardous organic chemicals Treatment of water for drinking by city dwellers is like wastewater treatment 64 contaminates are currently tested for in drinking water Privately-owned wells don’t have to meet federal drinking water standards

Groundwater Pollution and its Prevention Pollutants in drinking water is a high-risk health problem When is becomes contaminated, it cannot cleanse itself of degradable wastes Crude estimates indicate that up to 25% of usable groundwater in the US is contaminated Groundwater can be contaminated from a number of sources: Underground storage tanks Landfills Abandoned hazardous waste dumps Deep wells used to dispose of liquid hazardous wastes Industrial waste Livestock waste storage lagoons

Water Conservation Irrigation Line irrigation ditches high efficiency sprinkler system High-efficiency trickle or drip irrigation systems Computer-controlled systems to monitor soil moisture and irrigate as needed. Organic Farming – requires ~1/4 water of conventional farming. Industry Recycle aluminum (97% less water)

Domestic Xeriscaping (use of dry climate vegetation) and drip irrigation for gardens and other vegetation Eliminate leaks Water-saving devices (showerheads, toilets, appliances) Fewer and shorter showers “If its yellow, let it mellow. If its brown, flush it down.” How clean does your car have to be? Dishwashing? Depends….. Capture Rain water Turn water off when brushing teeth Full loads of laundry Mulch shrub beds Cover pool when not in use