GA Onsite - conventional

What is an auxiliary system?

a septic system meant to serve a portion of a residence or adjoining facility

What is the difference between black water and gray water?

Black water comes into contact with excrement/organic matter while gray water doesn’t

What is a percolation rate?

The amount of time, in minutes/inch, necessary for water to seep into saturated soil at a constant rate

Connection should be made to a sewer system if it is available within what distance?

200 feet

A septic system is required for facilities that have occupants for how many hours a day?

2 hours a day

A facility must pretreat waste if the TSS and BOD5 exceeds what limit?

200 mg/L

For sites less than 3 acres, what is the max perc rate to be considered for a conventional system?

90

For sites over 3 acres, what is the max perc rate to be considered for a conventional system?

120

What is the range for DPH septic tanks?

1,000 - 10,000 gallons

What is the minimum retention time for a septic tank?

24 hours

Septic tank setback for wells, springs, sink holes

50 feet

Septic tank setback for bodies of water

25 feet

Septic tank setback from property lines

10 feet

Septic tank setback for swimming pools, foundations

10 feet

Septic tank set back from pressure water supply lines

10 feet

Septic tank setback for drainage ditches, embankments

15 feet

Drain field setback for wells, springs

100 feet

According to an MOA with EPD, if a spring is not used for its water, how far away does the drain field have to be?

50 feet

Drain field setback for water supply lines

10 feet

Drain field setback for property lines

5 feet

Drain field setback for pools, drainage ditches

15 feet

Drain field setback for bodies of water

50 feet

Given it has no garbage grinder, a 1000 gallon tank is suitable for what size house?

a house with 1-4 bedrooms

How many additional gallons are added for each bedroom over 4?

250 gallons

If a facility has a garbage grinder, what does the septic tank capacity increase by?

50%

What should you do if a water supply line comes within 10 feet of the absorption field?

Encase the water line and install it at least 12 inches over the top of the aggregate for the absorption lines

What is the minimum requirement for liquid depth in a septic tank?

36 inches

What is the minimum amount of freeboard necessary in a septic tank?

9 inches

The 1st compartment in a compartmented septic tank must be what capacity?

2/3 of the total capacity

How much soil cover should be over a septic tank?

minimum of 6 inches

When are risers necessary for a septic tank?

When the soil cover exceeds 12 inches

What is the minimum thickness for a concrete septic tank?

2½ inches for the sides and bottom, 3½ inches for the top

Each septic tank shall be marked with what and where?

A stamp with the manufacturer and capacity to the right of the outlet, 6 inches from top of the tank

What side of the tank does your filter go?

outlet

Riser walls have a minimum thickness of what?

2 inches

In a concrete distribution box, the inlet should be how much higher than the outlet?

2-3 inches

In a plastic distribution box, the inlet should be how much higher than the outlet?

1.5 inches

In what situations are dosing tanks used?

• Where it is necessary to elevate the wastewater for further treatment or disposal

• Where intermittent dosing of treatment units or subsurface absorption fields is desired

• Where pressure distribution networks are used

When there are more than 500 linear feet of absorption trench, what is required?

A dosing tank and pump

When there are more than 1000 linear feet of absorption trench, what is required?

A dosing tank and alternating pump

A pump must have what to alert the owner of a malfunctioning system?

An alarm on a separate circuit from the pump switches

Absorption fields should not be placed in areas with a slope exceeding what?

25%

How far above the water table or other impervious layer should the absorption trench be?

24 inches

What is the minimum soil cover for absorption lines?

6-12 inches

Absorption lines should be how far apart, center to center?

7 feet

If a drain field were designed to allow for a replacement field to be placed in between the original absorption lines, how far apart would the absorption lines need to be, center to center?

16 feet

What is the maximum width of an absoroption line?

36 inches

Why should trench excavation not be done while the soil is saturated?

Damage to soil structure, such as smearing and compaction

Absorption field area is determined by what?

• anticipated peak daily volume of treated waste (# of bedrooms)

• waste stream characteristics

• soil characteristics (perc rate and depth to water table)

A concrete foundation extending how far beyond the distribution box is required?

12 inches

Beginning 2 feet from the distribution box to the beginning of the absorption line, independent sewer lines shall be installed to provide a minimum downward grade change of what from the outlet to the beginning of the absorption line?

2 inches

Coming out from a distribution box, absorption lines shall be installed level or on a uniform grade of no more than how many inches of fall for the entire length of the individual absorption line?

4 inches

The level field method may be used when the slope of the land is what?

5% or less

With the level field method, how much lower is the beginning of the absorption line from the outlet of the septic tank?

6 inches minimum

For the serial distribution method, how much lower is the first absorption line from the septic tank outlet?

4 inches minimum

An alternating absorption field system may be considered when the percolation is what?

between 60 and 90

Chamber systems may not be constructed of what material?

Metal

When is a grease trap required?

When a facility produces over 50 mg/L of grease that could be introduced into the system

Does a grease trap go before or after the septic tank?

Before

What is the minimum size of a grease trap?

125 gallons