Installation Instructions

5600 W. Douglas Avenue
Milwaukee, Wisconsin 53218
Phone: [phone] ▪ Fax: [phone]
Email: [e-mail]
www.heartlandlabs.com
Why Are Periodic Septic Tank Pump Outs Needed?
Removing septic tank sludge by pumping periodically is a critical step in maintaining a septic system. Periodic pump
outs will prevent septic system failure. The septic tank separates solids from liquids and should allow only clarified
liquids to enter the septic drain field for final treatment and absorption. Solid particles remain in the tank. Heavy solids
form the sludge layer, and light solids form the scum layer. Although more than half of the retained solids may liquefy
and decompose, the rest accumulate until removed by pumping.
If excessive solids are allowed to build up, the tank’s ability to clarify wastewater will be impaired. The capacity of the
tank decreases with sludge build up and liquids cannot be retained long enough to allow particles to settle out. If
particles enter the drain field and collect there, they will eventually cause drain field failure. In addition, if too much
sludge accumulates in the tank, solids may enter the drain field, clog it, and require replacement of the drain field.
The use of a quality septic system additive may prolong the recommended intervals between pumping by reducing the
amounts of sludge developed, but solids must always be pumped when the bottom sludge depth is within 18” of the
tank outlet pipes or if the top scum layer is within 3” of the outlet pipe.
What Variables Can Impact the Length of the Intervals Between Periodic Septic Tank Pump Outs Needed?
■ tank size ■ garbage disposal use in the home* ■ number of people living in the home
■ water usage in the home ■ type of septic tank additives used ■ frequency of tank additive use
(showers/week, shower duration, ■ characteristics of foods prepared ■ chemotherapy or chronic use of
loads of laundry/week, etc.) in home antibiotics by occupants of home
*Garbage disposals can increase scum accumulation by as much as 20%.
The only way to know for certain when a tank should be pumped is by inspection. Annual inspections are
recommended to determine the thickness of the scum layer and the height of sludge accumulation in the tank.
The septic industry has, however, developed standard recommended intervals for pumping conventional septic tanks
with year-round occupancy based on providing a minimum of 24 hours of wastewater retention assuming 50%
digestion of retained solids. These general guidelines are shown in the chart below. It is suggested that households
using garbage disposals should pump out their tanks 1-2 years sooner than indicated in the standard chart.
Industry Guidelines for Septic Tank Pumping Frequency
Pumping septic tanks according to these guidelines should extend the life of the septic drain field and spare the
substantial expense of repairs and replacements.
Source: State of NY
Number of People Living in Household
1 2 3 4 5 6 7
8 9+
Tank Size in gallons(m
3
) Recommended Years Between Pump Outs
500 (1.8) 5.8 2.6 1.5 1.0 .70 .40 .30
.20 .10
1000 (3.7) 12.4 5.9 3.7 2.6 2.0 1.5 1.2
1.0 0.8
1500 (5.6) 18.9 9.1 5.9 4.2 3.3 2.6 2.1
1.8 1.5
2000 (7.5) 25.4 12.4 8.0 5.9 4.5 3.7 3.1
2.6 2.2
2500 (9.4) 30.9 15.6 10.2 7.5 5.9 4.8 4.0
3.5 3.0