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Because of the subject matter, sewage treatment in the United
States has always been an un-popular topic of conversation. Consequently many
people are ignorant of the need for and the mechanics of this process. The
resulting health, environmental, property and financial damages is incalculable.
Lakes, rivers, streams, wetland habitat and oceans have suffered. Homes and
entire neighborhoods have been rendered worthless and unlivable. More than 1,200
Americans die every year from waterborne diseases and failing septic systems are
the number one source of these outbreaks. Although this situation is now being
addressed in most areas of the country, if this educational process were
implemented 30 years ago a lot of needless damage could have been avoided.
Prior to WWll, the bulk of the population lived in the cities close to the
work place. The city dealt with the wastewater generated by people and
businesses. With the economic boom generated by WWll, the late 1940’s saw a
tremendous exodus from the cities into the un-developed rural areas surrounding
the cities.
Because of the rapid growth rate, sewage treatment facilities could not keep
pace and these new communities were facing a major "what to do with the poop"
dilemma. Eventually it was decided these new homes would temporarily utilize
low-tech cesspools and in 5-7 years the high-tech marvels of modern science
would be available to these homeowners that were lucky enough to live in a free
democracy. You see, the cold war was not just fought with weapons of mass
destruction.
However, by the mid 1960’s these communities were facing another dilemma. The
expansion of sewage treatment facilities was far behind schedule and many of
these cesspools were beginning to fail. In fact, many of them had failed 2 or 3
times and the trend in the suburbs was to put homes on small lots so more tax
payers (homes) would fit in an area. The problem was, these small lots left no
room for a replacement. The result was, in many neighborhoods, the backyards
were turning into sewage swamps.
At this point many people began to realize that the smarter solution would be
to improve what was currently available rather than waiting for the treatment
facilities to catch-up. Much of the research was conducted by the Universities
of Minnesota and Wisconsin in the north central area of the country where lakes
are extremely prevalent and sport fishing/water recreation contributes to a
large part of the local economy through tourism. Many of these lakes were
experiencing a noticeable drop in water quality. If the quality of lakes were
allowed to continue to degrade, many tourists would look for other areas to
spend their vacations.
One of the first problems was cesspools provided very little in the way of
treatment. The common cesspool was a pit dug in the yard and rocks or bricks
without mortar were used to shore up the sidewalls, the whole affair would then
have some sort of top put in place and covered with topsoil.
As wastewater was flushed down the drain it would enter the "pit" where it
would migrate down through the bottom and through the sides. The thought process
at that time was to dig the pit deep to avoid the sewage surfacing on the
property. However, many of these disposal systems were nothing more than a
direct conduit to the underground water supplies. (see figure 1)
Figure 1

Figure 2
Of course these cesspools were also prone to failure as the inside of the
cesspool would become sealed with fats, oils, lint, grease, feces, etc. When
this happened the sewage would come to the surface where it would find it’s way
into surface waters, open wells and contact with people and animals. (see
figure2)
It was known however that certain types of soils were excellent mechanical
filters for removal of solids but as information was gathered and theories
explored it was found the naturally occurring bacteria in soils performed
another valuable service, they consumed the parasites and viruses present in
excrement. This, along with electrostatic processes that took place [in soils]
were found to be an excellent method of purifying wastewater.
There were of course limitations to this process, the contaminated effluent
had to pass through a minimum of 2 feet of dry soil. Dry soils contained oxygen
which supported aerobic bacterial colonies. Aerobic bacteria were found to be
approximately 20 times more effective than anaerobic bacteria that existed in
saturated soils.
It was also found the best zone of treatment took place in top 26 inches of
soil where oxygen levels were high. The deeper in the soil the less effective
the treatment process was. Below a depth of 6 feet the treatment process was
significantly hindered.
Another limitation was the permeable rates of soils. Highly plasticized clay
had the obvious problem of not allowing the migration of effluent at a suitable
rate. Course soils presented the opposite problem. The treatment process
required a certain amount of retention time and loose soils did not allow
adequate time for the processes to take place. In time, design methods were
found to alleviate these problems such as bringing the proper soils to the site.
By the 1970’s the typical design of a modern septic system was comprised of a
sealed tank for settling and storage of solids and a shallow trench system for
treatment and dispersal of liquid. (see figure 3)

Figure 3
The most popular tanks were usually constructed of reinforced concrete in
sizes of 500, 750, 1,000, 1,250 or 1,500 gallons. Tanks were also manufactured
in steel and fiberglass or plastic composites.
The septic tank is the first step of the wastewater treatment process.
All tanks (should) have inlet and outlet baffles, inspection pipes, and a
manhole for cleaning.
The inlet baffle forces wastewater entering the tank to slow and allow
the separation of solids, the heavier solids sink to the bottom forming the
sludge layer, the lighter solids float to the surface forming the scum layer,
the layer in the middle is a relatively clear layer called effluent. In the tank
the bacterial breakdown of organic materials begins. The inlet baffle also
prevents the floating scum layer from floating back and clogging the inlet pipe.
The outlet baffle prevents scum from leaving the tank. If the scum
layer reaches the outlet pipe, the pipe will become plugged. Scum in the
drainfield will clog soil pores and destroy its ability to treat wastewater.
Inspection pipes of 4- or 6-inch PVC (plastic) material should be
located above the inlet and outlet baffles to allow for inspection of pipes and
baffles. Clogs in the inlet or outlet pipes can be unplugged through the
inspection pipes. When operating properly, the septic tank is always "full' to
the level of the bottom of the outlet pipe. Some installations may have two
tanks in a row or one large tank with two compartments.
The manhole in the cover of the septic tank is a large entrance
(20"-24") through which the tank should be cleaned. The manhole is often buried
below ground level. It may be raised from the cover of the tank with concrete or
plastic rings for easier access. It is usually located in the center of the
tank; however, some manufacturers locate it closer to the inlet end of the tank.
There may be more than one manhole, in which case they are usually located at
the ends of the tank.
A typical drainfield is a trench or series of trenches approximately 3 feet
wide and 3 feet deep. Two feet of gravel are poured into the trench, 4 inch
plastic pipe with ½ inch holes is placed on top of the gravel, 6 more inches of
gravel is placed over the pipe and covered with a geo-tech fiber to prevent soil
from migrating down and clogging the gravel. Top soil is then used to cover the
trenches with a slight crown to encourage rain run-off.
As the effluent travels through this distribution pipe, gravity draws it
through the gravel-bed where the large openings between the pieces of gravel
create an excellent environment for naturally occurring aerobic bacteria
that begin consuming the disease-causing pathogens. The drainfield also acts as
a reservoir. At the interface of the trench sidewalls and bottom, a biomat of
dead and living bacteria forms and slows the rate at which the effluent drains
from the field.
The remaining pathogens are removed in the 2-3 feet of soil surrounding the
drainfield. A portion of the nitrogen and phosphates are wicked-up by the plant
life covering the field and the remaining nitrogen is changed to a gas form
and/or diluted. Approximately 30% of the liquid is returned to the atmosphere
through evaporation.
The Problems
In America, each of the 50 states has the ability to establish their own code
requirements as to what they consider adequate standards per sewage treatment.
Naturally some parts of the country are more advanced than others and in some
areas, the regulations have been relaxed to encourage development (tax dollars)
even though it is known the sewage is being inadequately treated.
Many contractors that design and install systems learned their trade from
their fathers, who learned it from their fathers. Years ago the purpose of
on-site systems was to dispose of waste water, not treat it. Many contractors
still adhere to this theory. At the same time, many inspectors, by their own
admission, are not trained to inspect on-site systems for defective
installations. A fair number of systems, because of faulty designs, will fail
with-in 3-5 years of use.
Homeowners are never given any information on the proper way to use a septic
system. Even people that have had their systems replaced multiple times are
seldom provided information (by the contractor) to prevent future problems or
are provided errant information by the contractor and friends.
Even the purpose of on-site treatment systems has never been explained. Many
homeowners are under the impression that septic systems are a temporary solution
as the city sewer is only a few years away and therefore have no incentive to
[long term] protect them.
Most homeowners are not aware of the damages from failing septic systems
because septic systems are not sexy environmental news stories. Often they are
passed over by the news agencies in favor of high impact news. Subsequently,
homeowners feel their failed system is only an inconvenience to them.
THE SOLUTION
By providing education at each level, these problems are significantly
reduced. When contractors are required to go through a training program and
certification process, there is a better chance that the systems being installed
will be proper systems.
If the regulators that inspect these systems are also required to participate
in this certification process, they will be much more qualified to catch and
correct any errors before they pose problems for the homeowners. By providing
education [to the homeowners that operate those systems] on how to properly use
those systems, failure rates drop significantly.
CONTRACTOR TRAINING AND CERTIFICATION CLASSES
These one, two or three day seminars are performed by Dave Gustafson of the
University of Minnesota Extension Service in association with the NAWT (National
Association of Waste Transporters). These seminars/certification classes have
been performed as both voluntary and mandatory process for contractors in
several states. To learn more about this program contact: Dave Gustafson
311 Bio Systems Ag Engineering
1390 Eckles Avenue
St Paul, MN 55108
1-612-625-1774 Fax-1612-624-3005
HOMEOWNER EDUCATION
Providing homeowners with clear and accurate information on the proper
operation of a septic system (and denouncing the many myths and misconceptions
that are so prevalent with on-site waste water treatment systems) these damages
are dramatically reduced without cost to the city, county or state.
The reason is simple, when a homeowner learns they may be drinking today what
they had for dinner last night, they more often than not will replace their
failing system on their own. Zoning officials have noticed a rush for up-grade
permits following these classes. When they learn how to use them, they don’t
fail.
These nation-wide classes have been performed by James vonMeier as a pilot
program for the University of Minnesota Extension Service. Contact:
James vonMeier
14622 268th Avenue
Zimmerman, Minnesota 55398
1-763-856-3800 Fax 1-763-856-3888 www.septicprotector.com
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