Lare Section 4: Utilities

Front 1

Proper site design for fire fighting

Back 1

1. Direct, easily perceived all weather vehicular access to each building and hydrant and/or to each surface water impoundment where applicable

2. Control massing of development with firebreaks or walls to reduce risk of conflagration

3. site layout allowing hoses to be run to all sides of each building

4. At least two hydrants within 500-600 ft of every building

Front 2

Sources of potable water

Back 2

1. public water supply

2. On-site wells or cisterns

3. surface reservoirs and ponds

Front 3

Surface catchments for potable water

Back 3

Must have a treatment system to clean the water and be able to store 1 years worth of water from the upstream catchment

Front 4

High-yield wells

Back 4

May be needed for new towns, require specialized expertise to plan and build. Good sites may include coarse outwash plains, ice channel fillings along valleys, river terraces, kame fields, and similar surficial deposits.

High yield wells often require a protected buffer zone in which other land uses are prohibited. These may be several hundred feet wide.

Should consider proximity to and possible contamination by seawater, organic deposits in marshes, urban land, and industrial waste.

Front 5

Wells in seacoast environments

Back 5

Water table must not fall below sea level or brackish water may enter potable water supply

Front 6

Wells near organic deposits

Back 6

Draw down cone may cause oxygenated water to come into contact with anaerobic organic deposits, releasing metallic sulfides into the water supply. Resting the well and allowing water table to rise can reverse these effects over time.

Front 7

Wells in or near urban or industrial development

Back 7

Recharge cone should not include developed areas or potentially contaminated sites unless analysis indicates no contamination risk exists.

Front 8

What type of effluent disposal can be used with a septic tank?

Back 8

All septic systems are limited to subsurface effluent disposal because of the odor inherent to septic effluent.

Front 9

Which is more expensive: individual on-site sewage disposal or a cluster system?

Back 9

A cluster system is more expensive, often by a ratio of 10:1 due to the need for pipelines, pumping stations, and manholes. Also higher operation cost.

Front 10

For what dwelling density is on-site sewage disposal appropriate

Back 10

5 DU/Acre for single family residences and 12 du/Acre for 3 story apartment buildings

Front 11

What site conditions must be met for on-site sewage disposal

Back 11

Adequate depth to groundwater and soil permeability

Front 12

Subsurface leaching system layout

Back 12

Front 13

Aerobic digester with surface infiltration bed

Back 13

Front 14

Aerobic digester with evapotransporation system

Back 14

Front 15

Unaerated lagoon for sewage disposal

Back 15

Front 16

Aerated lagoon for sewage disposal

Back 16

Front 17

Most effective, economical, and environmentally safe method for disposing of waterwater

Back 17

Slow filtration of wastewater through soil. Can be accommodated only if adequate space, permeability and depth to groundwater exist

Front 18

Septic system

Back 18

least-expensive small system

Front 19

Package plants

Back 19

aerobic systems for sewage disposal that can be employed if space or site conditions are constrained. Minature versions of municipal treatment plants, designed to settle out dissolved sewage and contaminants. Typically require periodic pumping

Front 20

Cesspool

Back 20

Front 21

How much unsaturated soil must there be between a septic leaching field and the water table?

Back 21

Typically about 1m. Can be achieved via mounding if underlying soil is permeable

Front 22

Septic tank maintenance

Back 22

1. Infrequent pumping to remove nondegradeable solids

2. Resting of the leaching facility

Front 23

How long can a septic tank function before it should be rested?

Back 23

20 years. Site layout should leave space for two septic leaching fields even though often only one is built initially.

Front 24

What determines the infiltration rate of effluent?

Back 24

The permeability of the bacterial slime generated by the effluent itself, which is often much less permeable than the soil.

Front 25

Disadvantage of unaerated lagoon for sewage treatment in cold climates?

Back 25

In cold climates sewage lagoons will turn over twice a year, which has a strong odor. Aerating the lagoon year-round can mitigate that effect

Front 26

Can evapotranspiration systems be used with effluent from septic systems?

Back 26

No, effluent must be aerobic to be taken up by plants.

Front 27

What uses are compatible with an evapotranspiration system for sewage disposal

Back 27

Typically none while field is active. When inactive compatible uses may include crops not used for human food, game habitat and hunting grounds, forest products, and forage crops for horses.