Environmental Controls I IG Lecture 6 Overview Water Resources

Environmental Controls I/IG Lecture 6 Overview Water Resources Water Supply Systems Planning Issues

Terminology Potable Water: water fit for human consumption Gray Water: non-potable, used water containing no harmful wastes Black Water: non-potable, used water that contains harmful or human waste

Drains and Sewers Storm: contains rainwater and surface runoff Sanitary: contains human waste Combined: contains both

Acid Rain combined with chemicals (SO 2, COx, NOx, …) in the air to form a weak acid Water + Sulfur Dioxide = H 2 O + 2 SO 2 Sulfuric Acid H 2 SO 4 + SOx Source: automobile emissions, coal fired electric generation, air pollution

Hardness Caused by calcium and magnesium salts Can be removed by “water softening” systems

Ph Scale Alkalinity: bicarbonates, hydroxides (Ph>7) Acidity: hydrogen ions (Ph<7)

Water Table Naturally occurring depth to top of water in an aquifer S: p. 896, F. 21. 2

Water Resources

Sources of Fresh Water Precipitation collection Surface water diversion Groundwater aquifers Desalinization

Hydrologic Cycle Water exists in three phases—vapor, liquid, solid Water storage takes several forms– clouds, groundwater, snow/ice, lakes/river/oceans S: p. 859, F. 20. 4 a

Hydrologic Cycle Natural intercepts of water affect its purity and utility S: p. 859, F. 20. 4 b

“We All Live Downstream” Human intercepts degrade quality S: p. 896 F. 21. 2

Toxins Around Us Arsenic: pressure treated lumber Cadmium: batteries Chromium: antifreeze Fluoride: rat poison, water treatment Lead: paints, piping, fuel Silver: photo-processing

Other Contaminants Chlorides (road salts) taste Copper (corroding pipe) taste Iron (corroding pipe) stains/taste Manganese (natural) taste/laxative/color Nitrates (fertilizer) health Pesticides health Sodium (road salt) taste

Water Supply Systems

Groundwater Aquifer Artesian wells created from pressure due to elevation head 2. 3’ of head = 1 psi

Upfeed System Supplied through pressurized street main or artesian well source S: p. 958. F. 21. 52

Cisterns Captured rainwater held in tanks to increase water availability and pressure May also be refilled manually San Francisco Plantation, Louisiana

Enhancing Water Pressure When natural pressure is insufficient then a pump or pressurized source must be used S: p. 913, F. 21. 13

Water Towers Used before electric pumping technology improved Hand pumps or manual labor Baltimore, MD Chicago, IL Scituate, MA

Water Towers Adapted for use on individual buildings S: p. 959, F. 21. 53

Pumping Technology As technology improved, buildings could become taller (w/steel framing and elevators) Downfeed system S: p. 960, F 21. 54 a

Pumping Technology Constant pressure up-feed system eliminates the house tank S: p. 965, F 21. 57

Pumping Technology To prevent overpressurization, intermediate house tanks are used S: p. 961, F. 21. 54 b

Planning Issues

Planning Issues Conservation strategies Facility requirements Waste disposal

Conservation Strategies Reduce use flow control fixtures Match grade to use culinary vs. irrigation Collection/Storage cisterns, retention basins, roof ponds, porous pavement Graskrete

Conservation Strategies Gray Water Systems: captures drainage from non-black water waste fixtures and reuses it for lesser quality needs …irrigation, car washing… Recently legalized in Utah. Opposition was due to contamination concerns and inappropriate soil composition

Conservation Goals Reduce overall consumption Avoid surface runoff Allow percolation into soil to recharge groundwater table

Facility Requirements Check local codes for programming & ADA requirements S: p. 864, T. 20. 3

Waste Disposal Verify local sewer system availability/capacity n n Municipal sewer Septic system on site n n n Soil percolation Drain field/septic tank location Drain field proximity to other water sources

Water Reclamation Municipal programs that use treated wastewater for uses that do not require potable water Los Angeles County Water Reclamation Project