FEATURE
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1 2
Ian Dickie
1 and 2: Ian Dickie’s pumps on site at Saldanha Bay.
Specifically, septic pumps, sewage pumps and sewage
ejector pumps are designed to remove sewage – with
solids up to a certain size - from a building where plumbing
fixtures and drains are lower than the building sewer line
and/or septic tank. Septic pumps must move solids, either
by being able to pass large solid objects through the pump
without clogging, or by grinding the solids into fine debris.
A sewage grinder pump is designed to macerate solid
waste so that it can be pumped through a sewer line —
perhaps a smaller diameter ‘force main’ sewer line to a
public sewer or septic tank.
Sewage grinder/ejector pumps are available in various
horsepower models, typically from .5 to 1hp for residential
applications, and are sold to operate at various voltages,
including 110–120V, 220–240V, 440–480V, and even 600V
models using either single-phase (most common) or threephase
motors.
People use terms loosely, specifically the terms sewage
pump and septic pump are viewed as synonyms. Indeed,
both classes of pumps handle black water or sewage — only
the destination differs. A sewage pump, strictly speaking, is
pumping black water (toilet waste) to a public sewer line; a
septic pump, on the other hand, is pumping black water to a
private septic tank and drain-field system.
Therefore, it is important to ask for or to read the
manufacturer’s description of what a particular pump model
is intended to handle. In addition, even among sewage
pumps and grinder pumps that are intended to either pass
solids or grind solids up and pump them, the vulnerability
of different pump models to damage, clogging, or motor
burn-up from debris that people may flush down drains and
toilets varies.
Sump pumps are designed to remove unwanted water, such
as surface or ground water that leaks into a building. Sump
pumps only have to pump water, never solids. A sump pump
is normally installed in a pit at the low end of a basement or
crawl space floor.
According to Sapsda, the various sectors that a pump system
would consist of, are as follows:
• Pumps
• Electrical Motors and Drives
• Sealing Systems
• Bearings
• Couplings and Mechanical Drives
• Control Valves
• Electrical Cables
• Switchgear and Control Panels
Be sure to select the proper septic – or sump pump – type.
How to choose an effluent pump
Septic effluent pumps are used to move clarified septic
effluent from a pumping chamber to a drain field. They
do not have to move solids, but are built to standards of
durability more demanding than a typical sump pump used
to remove ground water from a building.
Pump manufacturers may claim that the same pump model
can serve as a sump pump, effluent pump, and dewatering
pump. However, that is not universally the case: while some
sump pumps work fine as effluent pumps, others, such as
low-cost sump pumps using a vertical float and rod switch
and intended for indoor dewatering in basements, may not
be suitable for septic effluent pumping.
Be sure to select the proper septic- or sump-pump type. The
distinction among sewage pumps or septic pump types is
important when installing or repairing a septic system that
uses pumps, since choosing the wrong pump can mean a
short operating life for the pump, an unreliable septic system,
and unnecessary expenses. If you’re replacing an old effluent
pump, you can typically use the same horsepower that you
had before. That said, you should also pay close attention to
the litres per hour rating as they can vary by horsepower. If
your pump wasn’t keeping up, you may need to upgrade to a
higher horsepower so it can keep up.
If you were able to get several years of service out of your old
pump, chances are that it’s the right horsepower to choose.
If your previous pump stopped working after a couple of
months, you may want to consider a different horsepower.
It’s possible that your old pump may have been too weak or
too strong for your application.
“As a
plumber, if
you install an
inappropriate
plumbing
pump, the
results could
be both
devastating
and costly.”
August 2020 Volume 26 I Number 06
www.plumbingafrica.co.za