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Ill identify an acceptable on-site sewage disposal system. Necessary due to wide variation of soils and their ability to absorb water.
septic tank minimum requirements
- 1000 gallons;
- minimum liquid depth of 3ft;
- maximum liquid depth: 6 1/2ft;
- minimum air space of eight inches in tank;
- all require removable manhole cover or 24-inch manhole opening;
- walls 2-3.5 depending on which
- Shall be located downstream of septic tank;
- designed to pump sewage/particles/solids;
- manhole opening must be at least 2 inches above ground and have a manhole opening of 24 inches;
- discharge line of 1-1/4 to 1-1/2 inches in diameter;
- pump compartment minimum 300 gallons;
- must have air gap to prevent back siphoning.
? Septic tank must have minimum 3-4 lateral lines (dumping lines)
?MAY have up to 6
Subsurface absorption field - use lots
Must be free of surface water/runoff. Any of this must be diverted away. Minimum area is 10ft^2. All wastewater including laundry and kitchen waste must be connected.
Unless a mechanical lift pump is used, all perforated pipe shall be located at at least 6 in. below liquid level of septic tank.
All sewer drains and stub outs shall be installed so that it is no deeper than 30in. below natural ground level for lateral field area.
retention structures shall be used. Inlets and outlets of retention structure must be sealed. Top of pipe in lateral line at least 10 inches below the outlet of septic tank.
must be built if perc test states a septic tank is not suitable. Common in the country where the soil is clay-like.
Perc test procedure
At least three tests to define absorption field.
A failing test is a drop of less than 1 inch in 10 minutes.
Test holes 4-12 inches in diameter 24-30 inches deep.
Holes placed at approximate corners of isosceles triangle having two sides 50x75ft.
Ex: drop of 3 inches in 60 minutes = 20 minutes per inch.
Soaking is used to simulate conditions during the wet season.
Swelling is intrusion of water into soil particles. Slow process - especially in clay.
Perc test interpretation
If all three test sites have a drop of 1 inch or more in 60 minutes.
Add sum of three depths together and divide by sum of three times to get average percolation rate. Use table to determine length of lateral lines.
If any two tests are more than 15 minutes apart; rate of slower is used.
If any one test fails; a suitable absorption field has NOT been found.
unwanted or offensive sounds that unreasonably intrude into our daily activities.
Factors for increasing noise pollution:
- Increasing population
- increasing volume of road, rail, and air traffic
Prolonged exposure to noise levels at or above 80dB(A)
Average traffice noise:
Noise and land zoning:
Separation of activities which are incompatible due to noise levels. For example: heavy industry will be separated from residential areas by light industry, recreational facilities, or retail.
Noise Control Act 1975
Noise Control Regulation 1995
Controls noise on building alarms; night-time control of noise sources: power tools, lawn mowers, AC, music. Warnings valid for 28 days; horns, refrigeration units.
Indoor Air Pollutants
Oil, gas, kerosene, coal, cood, tobacco, abestos, personal care items, heating and cooling devices, hudifiers, radon, pesticides, outdoor air pollution
If too little outdoor air enters a home, pollutants can accumulate to levels that pose health and comfort problems.
O3 - should occur 10-30 miles above ground level. Ground level ozone is bad.
Ground level is created by a reaction between oxides and nitrogen (NOx) and volatile organic compounds (VOC). NOx and VOC main source is from emissions
VOC + NOx + Heat + Sunlight = Ozone
Peak is summertime when hot and dry
Can be carried hundreds of miles
Ground level ozone affects health and plants/ecosystem damage
Clean Air Act set the National Ambient Air Quality Standards for six principal pollutants in ppm:
- Carbon Monoxide
- Nitrogen Dioxide
- Particulate Matter (10) dust, soot, smoke
- Particulate Matter (2.5) burned gases
- Sulfur Oxides
Sulfur Dioxide SO2
65% from electric utilities (coal), industry
Contributes to acid rain
Carbon Monoxide (CO)
Colorless, odorless gas formed when carbon fuel isn't burned completely.
Motor vehicle ehaust = 56%
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) 1980
Created a tax on chemical and petroleum industries -- over 5 yrs, $1.6 billion collected and put into a trust fund for cleaning up abandoned or uncontrolled hazardous waste sites
- Authorizes two kinds of responses:
- Short term removals for threatened releases requiring prompt response
- Long term remedial for situations that are not immedately life threatening
Amended by Superfun Amendments and Reauthorization Act (SARA) in Oct 1986 - stressed permanent solutions, focus on human health, new enforcement authorities and tools, increased size of trust from 1.6 to $8.5 billion
Can't be exceeded more than once per year
Annual arithmetic mean PM10 can't exceed 50ug/m^3
3 year average PM2.5 can't exceed 15ug/m^3
98th percentile of 24hr average can't exceed 64ug/m^3
3 year average of 4th highest daily maximum 8-hour average ozone concentrations must not exceed .08ppm.
Winterizing and securing outdoor pools
All gates shall be locked. All outdoor pools should be secure in one of the three ways:
- 1. Draining
- 2.not drained or covered -- turbidity controlled to be able to see main drain from pool deck. Maintain disinfectant levels.
- 3. Covering must be able to support 1000lbs. with no water on top. If water is left in the pool, it should be below skimmers (18-24"). Lights should be taped OFF.
- Humans: 10-14 days
- Cats & dogs: 3-5 days
- Bats: 2 weeks
4 or more rooms OFFERED on a daily basis
ice machines must eliminate human contact
Primary sewage treatment
removes 40% suspended solids and 30-40% of BOD
- screening large objects
- grit chamber
- sedimentation tank
Secondary sewage treatment
removes 85% BOD
activated sludge - microorganisms to break down organic material with aeration and agitation
Trickling filters - beds of coarse media (often stones or plastic 3-10ft deep)
Lagoons - slow and cheap. Rely on interaction of sunlight, algae, microorganisms, and oxygen
exposing to circulating air; adds oxygen to wastewater and allows other gases trapped in the wastewater to escape (first step in secondary treatment via activated sludge).
biochemical oxygen demand (BOD)
Lab measurement of wastewater that is one of the main indicators of the quantity of pollutants present; parameter used to measure the amount of oxygen that will be consumed by microorganisms.
Sludge that is intended for beneficial use (fertilizer, soil amendment)
treated wastewater from a lagoon, tank, treatment plant, etc.
Total suspended solids (TSS)
Lab measurement of the quantity of suspended solids present in wastewater that is one of the main indicators of the quantity of pollutants present.
50 gallons per person per day minimum
Chlorinated to 50-100ppm
100 gallon well - use 14-28 ounces cleach; let sit overnight, flush, wait a week and test.
safe water distance from pollution
- 50 uphill from pollution
- 75 same elevation
- 100 downhill from pollution
private wells must be at least 10ft below ground surface
needs watertight casing; should extend to at least 8" above ground
Formulas & Conversions
volume cylinder = pi x h x r^2
1ft^3 = 7.48gallons
Flow = 8.34mg/l
1gal water = 8.34lbs.
Elevation of pump above source of supply cannot exceed _____.
Dissolved oxygen is highest in a lake at:
3pm or later, had all day to synthesize
Common settling times in wastewater treatment plants
Rock in most trickling filters is placed___
directly on the ground
used to measure flow of wastewater
exhaust from a chlorinator room should be taken from
chlroine residual may be determined using reagent
Dresser and victaulic couplings are commonly used with _____ piping.
Loading rate, solids concentration, DO are used in _____.
activated sludge process
amperometric titrater is used to measure ___
Adding sodium thiosulfate is to:
remove any residual chlorine
Waste retention tank on a mobile food prep unit must be___
at least 15% larger than potable water system