Water Systems

Plumbing Systems

CNST 305 Environmental Systems 1Dr. Berryman

3a Water System Chapter 8; Appendix B (Wentz) and 8.1-  8.3 (Toa)

4.11 Analysis and Design of Construction Systems - Mechanical (6 hrs)

Earth’s Water Supply

97% of the earth’s water is inaccessible. Mostly in the polar caps or ocean water

That 3%… Aquifers Cisterns Rivers/Lakes

Aquifers – Water Table

Water Table

Drilled Well

Nebraska Aquifers 0’ – 260’

Cost to drill a well - $8.00/ft + pump ($2500 for 1.5 hp submersible)

Cisterns

Used in areas where potable water is difficult to obtain

Solar Collection

Water Quality Based on

Physical characteristics• Limited amount of suspended material

(cloudiness, clarity, acceptable taste, odor, temp)• Measured in turbidity units (<5 TU)

Chemical Characteristics• Limited to the amount of dissolved matter• Preferred hardness

(< 200ppm or <11.7 grains per gallon) Biological and Radiological Characteristics

• Should be practically free of bacteria, viruses, and radioactive material

Water Analysis Sulfate

• Over 300 – 500 ppm produce a laxative effect for those that have not adapted

Nitrate• Over 10 ppm – health problem for infants• > 50 ppm – very undesirable, health risks

Fluoride• Control tooth decay at 0.9 – 1.5 ppm• Concentrations over 3.0 cause mottling of

the teeth

1 ppm = mg/l = 1 mg/kg divide by 17.1 to get grains per gallon (gpg)

Water Analysis (cont.) pH

• Between 6.5 – 8 is acceptable

Iron and Manganese• Stain cloths and plumbing fixtures• Problems (iron>0.3 ppm;manganese>0.2 ppm)

Sodium• Problem w/ salt diets (more than 100 ppm not

desired)

Calcium Carbonate

Calcium Carbonate Calcium Carbonate

Desirable <200 ppm• Less than 100 ppm: – soft water• 100 – 200 ppm: reasonably soft• 200 – 300 ppm: avg hardness• 300 – 400 ppm: very hard• Over 400 ppm: extremely hard

Too hard• More soap required to produce lather• Causes rings in bathtubs and sinks• Chemical deposits in pipes• Poor laundry results• Hard water not considered detrimental to health

Water Quality Improvements Sedimentation Coagulation (or flocculation “floc”) Aeration Disinfection Fluoridation Filtration Softening

RO systems• Micro pre-filter• Carbon pre-filter• RO membrane• Carbon post filter

residential commercial

Water Softeners The most common

method for point-of-entry (POE) treatment is cation exchange. A cation is a positively charged ion, both the hardness minerals calcium (Ca) and magnesium (Mg) are cations. To remove them from water the hardness cations are exchanged with sodium ions (also a cation).

There are four components to a softener unit: a control valve (1),  a saline tank (2),  a resin bed (3), and a resin tank (4). The resin tank holds the resin bed,  the brine tank  holds water and dissolved salt solution (brine). The control valve sits on top of the tank.

Water Samples

Cross Connections Any connection or arrangement

between two otherwise separate piping systems, one of which contains potable water and the other contains water of questionable safety, whereby flows from one system to the other.

FILM

Cross Connection Prevention Check Valves Air Gaps Vacuum

Breakers Backflow

Preventors Double check

valve system w/ vacuum breakers

Next Time Hot Water Engineering Design

3bc Water System Chapter 8; Appendix B (Wentz) and 8.1-  8.3 (Toa)

4.11 Analysis and Design of Construction Systems - Mechanical (6 hrs)