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Household Water Systems. Household Water System Components. Water Source (well, spring, pond, or cistern) Pump Pressure Tank Pressure Switch Check Valve Piping Optional Treatment Equipment (Softener, Filter, Disinfection Unit, etc). Typical Shallow-Well Water System.
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Household Water System Components • Water Source (well, spring, pond, or cistern) • Pump • Pressure Tank • Pressure Switch • Check Valve • Piping • Optional Treatment Equipment (Softener, Filter, Disinfection Unit, etc)
Typical Shallow-Well Water System SUPPLY PIPE TO HOUSE PUMP POWER CONTROL BOX SUCTION PIPE PRESSURE TANK PRESSURE SWITCH CHECK VALVE WELL CASING SHALLOW-WELL JET PUMP
PRESSURE SWITCH Pump House with Shallow Well Pump
Jet Pump Installations Deep-Well Jet Pump (Two-Pipe System) Shallow-Well Jet Pump
Jet Pump Schematic Diagram • Increases practical suction lift by diverting part of the pump discharge to the ejector on the lift pipe • The greater the suction lift, the greater the percentage of discharge water must be diverted • Maximum practical lift is limited to approximately 200 feet by economics To Pressure Tank Pressure Pipe (Return Flow) Lift Pipe (Upward Flow) Jet Ejector (Venturi) Nozzle Intake Pipe Water
Deep-Well Jet Pump Ejector Units Packer System Return Flow Lift Pipe (w/ Venturi) Nozzle Foot Valve Packer Suction Pipe Two-Pipe System Well Cap Return Pipe Lift Pipe (w/ Venturi) Nozzle Foot Valve Intake Strainer
Submersible Water Pumps • - Good for deep wells • High efficiency • Wells as small as 4” diameter
FROST LINE Submersible Pump with Pitless Adapter
Pressure Switch • Controls water pump • Turns on when system pressure drops to 20 (30) psi • Turns off when system pressure rises to 40 (50) psi • Low pressure shut-down in case well water level drops
Pressure Tank • Is not meant to provide household water storage • Delays pump turn-on and extends pump run time • Eliminates frequent, short On/Off cycles which can burn up the pump motor • Volume of pre-charged tank should be at least 6 times the delivery of the pump in 1 minute • Volume of uncharged tank should be at least 10 times the delivery of the pump in 1 minute
Pressure Tank Pipe Plug (to be removed when system is drained to correct waterlogging) Typical uncharged pressure tank (no air bladder/diaphragm) installation Pressure Switch Main Power Cutoff Switch Delivery Pipe from Pump
Useable Storage Capacity of Pressure Tanks Over Normal Operating Range (Not Pre-charged) 82 gallons Water Level at 12 gallons 42 gallons 40 lbs 20 lbs
Waterlogging Pipe Plug (to be removed when system is drained to correct waterlogging) • To correct waterlogged pressure tanks: • -Turn off power to pump • Open a faucet to drain system • Remove pipe plug at top of tank to let air into tank and finish draining system • Replace pipe plug (use teflon tape or pipe compound to seal properly) • Close faucet • Turn on power • Repeat this process whenever the pump begins starting immediately every time a faucet is opened Power Switch
Submersible Pump Check Valve Cutaway Water Flow
Household Water Requirement • Typical Usage: 50-100 gallons/person-day (drinking, bathing, laundry, toilet flushing, dishwashing, cooking, etc.) • Well Flow Rate Requirement: • Minimum Acceptable Rate: 5 gpm • Preferred Rate: 10 gpm • Minimum Fire Protection Rate: 20 gpm
Intermediate Water Storage • Improves usability of low-yield wells • Well pump operates at low flow for extended periods (overnight) to fill storage tank • Pressure pump uses water from storage to supply immediate household demand • Minimum intermediate storage capacity should be at least equal to daily household water use (2-3 days’ storage capacity preferred)
Low Yield Well Water System Inlet from Well Pump Intermediate Storage Tank (filled by submersible well pump) Pressure Pump Check Valve Pressure Tank Pressure Pump Suction Line Supply Line to House
Water Treatment Equipment • Disinfection Equipment • Filters • Water Softeners
Water Disinfection Options-Bacteria & Viruses- • Chlorination • Shock chlorination • Continuous chlorination • Dry pellet chlorinator • Chlorine solution feed pump • Chlorine solution venturi injector • Ozonation • Ultraviolet Irradiation
Shock Chlorination • Use laundry bleach (5.25%) w/ no additives • Pour 4 pints of bleach into well vent for each 100 gallons of water in system • Recirculate water into well for 20 minutes • Open all outlets until bleach is smelled • Let system stand idle overnight (4 hrs minimum) • Flush system • Re-test for bacteria after 10-14 days of use
Dry Pellet Chlorinators • -Electric powered (110 or 220 volt) • -Controlled by pump controller • Few moving parts • Uses calcium hypochlorite tablets • Treats water in the well • Longer Cl contact time • No solutions to mix • Treats up to 20 gpm
Venturi Solution Injector • Injects any liquid solution • Injection rate proportional to water flow rate • Adjustable over wide range of flow and injection rates
Metering Pump • Injects any type of solution • Controlled by water pump controller • Constant injection rate • Adjusts to wide range of flow and injection rates
Ultraviolet Disinfection Unit SIGHT PORT
Water Treatment Options- Iron or Manganese - • Shock Chlorination • Continuous Chlorination • Dry pellet chlorinator • Chlorine solution feed pump • Chlorine solution venturi injector • Ozonation • Oxidizing (Greensand) Filter • Ion Exchange Water Softener
Water Treatment Options-Corrosion- • Neutralizing Filter • Limestone chips • Marble chips • Caustic Soda (NaOH) Feeder • metering pump or venturi injector • Soda Ash (Na2CO3) Feeder • Metering pump or venturi injector
Water Treatment Options-Hydrogen Sulfide (H2S) “Rotten Egg” Odor- • Activated Carbon Filter • Oxidizing Filter • Shock Chlorination • Continuous Chlorination • Dry pellet chlorinator • Chlorine solution metering pump • Chlorine solution venturi injector • Ozonation
TDS/Mineral Treatment • Reverse Osmosis • Distillation
Reverse Osmosis Systems • Reduce mineral concentrations by 90% • 15 gallon/day under-sink units: $150-$300 • Require pre-softening with hard water • Operate on water system pressure (40 psi) • Wastewater:Treated water ratio 4 or 5:1 • Membranes: $70-100 each; 5 year life
Distillation Unit Vaporization Chamber Gas Vent Condensing Coil Raw Water Inlet Rising Steam Distilled Water Drain Heating Element
Countertop Distillers • initial cost $150-$1000 • 4-8 hours/gallon treatment rate • 2.75-3.0 kWh/gallon energy consumption • removes 99.9% of all contaminants • electric co-ops often subsidize purchase
Carbon Filters • Remove contaminants by adsorption on carbon particle surface • Hierarchy of contaminant adsorption • Saturated filters can actually increase concentration of some contaminants • Not effective on nitrate, hardness or bacteria • Filter cold water only • Bigger is better - more surface area
Cartridge Filters Carbon Cartridge (taste, odor, chlorine, organics) Particle Cartridge (sand, sediment) Filter Wrench Filter Housing
Ion Exchange Water Softeners • Exchange sodium ions for calcium and magnesium ions in water • Increase EC somewhat • May be dietary hazard - hypertension (adds 140 mg/l of sodium in “Hard” water) • Use potassium salt (KCl) for health reasons
Ion exchange softeners replace Ca++ and Mg++ with Na+ ions. Zeolite medium is recharged with Na+ by NaCl brine when depleted.
Ion Exchange Water Softener with Sensor- Controlled Recharge
Softener Selection Considerations • Required grain capacity • Daily water use (household population) • Water hardness • Desired regeneration schedule • Initial cost • Water conservation • Other (Iron removal, etc.)
Ion Exchange Water Softener Capacity • Rated by grains of hardness treated between regenerations • 1 grain/gallon (gpg) = 17.1 mg/l Example: Water hardness = 200 mg/l = 200/17.1 = 11.7 gpg Softener Capacity = 30,000 grains Household Population = 4 persons Calculate: Water Use = 4 persons x 50gal./person-day = 200 gal./day Daily Hardness Treated = 200 gpd x 11.7 gpg = 2339 grains/day Regeneration Interval = 30,000 grains/ 2339 grains/day = 12.8 days