Household Water Systems

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Household Water Systems

Household Water System Components: 

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)

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Typical Shallow-Well Water System PUMP POWER CONTROL BOX SHALLOW-WELL JET PUMP CHECK VALVE WELL CASING SUCTION PIPE SUPPLY PIPE TO HOUSE PRESSURE TANK PRESSURE SWITCH

Water Pump Options: 

Water Pump Options

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Pump House with Shallow Well Pump PRESSURE SWITCH

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Jet Pump Installations Shallow-Well Jet Pump Deep-Well Jet Pump (Two-Pipe System)

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Intake Pipe To Pressure Tank Pressure Pipe (Return Flow) Lift Pipe (Upward Flow) Jet Ejector (Venturi) Nozzle Water 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

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Deep-Well Jet Pump Ejector Units Two-Pipe System Well Cap Return Pipe Lift Pipe (w/ Venturi) Nozzle Foot Valve Intake Strainer Packer System Return Flow Lift Pipe (w/ Venturi) Nozzle Foot Valve Packer Suction Pipe

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Submersible Water Pumps - Good for deep wells High efficiency Wells as small as 4” diameter

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Submersible Pump with Pitless Adapter FROST LINE

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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: 

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

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Pressure Tank Typical uncharged pressure tank (no air bladder/diaphragm) installation Pipe Plug (to be removed when system is drained to correct waterlogging) Pressure Switch Delivery Pipe from Pump Main Power Cutoff Switch

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Useable Storage Capacity of Pressure Tanks Over Normal Operating Range (Not Pre-charged) 42 gallons 40 lbs 20 lbs Water Level at 12 gallons 82 gallons

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Examples of Pre-charged Pressure Tanks

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Effect of Waterlogging on Useable Pressure Tank Capacity

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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 Pipe Plug (to be removed when system is drained to correct waterlogging) Power Switch

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Controlling Waterlogging in Pressure Tanks

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Submersible Pump Check Valve Cutaway Water Flow

Household Water Requirement: 

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

Household Water Requirements: 

Household Water Requirements

Farmstead Water Requirement(Flow Rate): 

Farmstead Water Requirement (Flow Rate)

Intermediate Water Storage: 

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)

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Intermediate Storage for Low-Yield Wells

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Intermediate Storage Tank (filled by submersible well pump) Pressure Tank Pressure Pump Low Yield Well Water System Inlet from Well Pump Pressure Pump Suction Line Supply Line to House Check Valve

Water Treatment Equipment: 

Water Treatment Equipment Disinfection Equipment Filters Water Softeners

Water Disinfection Options-Bacteria & Viruses-: 

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: 

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

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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

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Venturi Solution Injector Injects any liquid solution Injection rate proportional to water flow rate Adjustable over wide range of flow and injection rates

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Metering Pump Injects any type of solution Controlled by water pump controller Constant injection rate Adjusts to wide range of flow and injection rates

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SIGHT PORT Ultraviolet Disinfection Unit

Water Treatment Options- Iron or Manganese -: 

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

Iron Treatment Options: 

Iron Treatment Options

Water Treatment Options-Corrosion-: 

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-: 

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: 

TDS/Mineral Treatment Reverse Osmosis Distillation

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4-stage Reverse Osmosis Unit with Tank and Faucet

Reverse Osmosis Systems: 

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

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Distillation Unit Heating Element Vaporization Chamber Condensing Coil Gas Vent Raw Water Inlet Distilled Water Rising Steam Drain

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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: 

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

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Cartridge Filters Filter Wrench Filter Housing Carbon Cartridge (taste, odor, chlorine, organics) Particle Cartridge (sand, sediment)

Ion Exchange Water Softeners: 

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

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Ion exchange softeners replace Ca++ and Mg++ with Na+ ions. Zeolite medium is recharged with Na+ by NaCl brine when depleted.

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Ion Exchange Water Softener with Sensor- Controlled Recharge

Softener Selection Considerations: 

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: 

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

Recommended Softener Sizes: 

Recommended Softener Sizes

Ion Exchange Water Softener Recharge Control Method: 

Ion Exchange Water Softener Recharge Control Method -Time Clock -Flow Meter -Hardness Sensor Water Use + - Initial Cost - +

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Typical Programmable Water Softener Controller

Water Softening: 

Water Softening Permanent magnet water softeners don’t work Electrostatic and catalytic descalers may “descale” water, but don’t soften it Scale will not buildup on pipes, water heater elements, bathtubs etc. Sudsing action of soaps is not improved

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Private Water System Resources