Waste management is as old as human civilization although the invention of septic tanks didn’t come until the 1860s.

Even then, the systems were anything but perfect but our forefathers continued innovating and improving and the septic tank revolution continued until we had what we have today.

When concrete tanks were introduced, they were molded using planks of wood after which concrete was poured.

But in the 1970s, precast tanks were introduced and that helped to bring costs down while also increasing the efficiency of the septic systems.

The Septic Tanks Of The 1970s

The first precast tanks of the 1970s were made of metal as opposed to concrete and they were commonly referred to as dickey tanks.

Dickey tanks were typically 500- gallon tanks that had round metal vessels that served as lids.

They were mass-produced and shipped out to lots of homes in the country and some of them are still in use to date.

Coincidentally, this was also the time when ordering an entire house as a kit became popular.

 So, it was not uncommon for people to order an entire house with a precast tank as an add-on.

But even though precast tanks began gaining traction in the 1970s, the age-old practice of building tanks on-site was still pretty common.

And these tanks were designed differently from what we currently have.

For instance, in 1995, a new code was introduced that allowed for an open tee as an inlet instead of the 90-degree elbow that was traditionally used in older systems.

Interestingly, some modern septic tanks decay a lot quicker than the older ones.

For instance, many homeowners have observed significant deterioration of some new tanks when pumping them for the very first time (within 2-5 years of installation).

Meanwhile, the older tanks seem to be standing the test of time and some seem to be even sturdier than modern ones.

In fact, if you buy a house that was built in the 1970s, there is a good chance it will have one of these old tanks.

There are many reasons why older tanks seem to last longer but the most logical reason would be the materials used and how the tanks were actually made.

For starters, some of the tanks were not mass-produced and were instead built on-site with a contractor.

Secondly, it was pretty common practice to add some other layer of protection to the septic tank as a measure against pollution.

For instance, San Diego Country required any new septic tank to have an emulsion coating inside it.

However, these requirements have since been deprecated due to the supposed improvement in cement and building technology.

Notable Differences Between 1970s Septic Tanks And Modern Designs

Materials Used

The first notable difference is the materials used.

1970s septic tanks were primarily built using concrete although precast metallic tanks were also used.

Fiberglass was also used in the 1970s but it was not as common.

Today, there are lots of materials that a user can choose from.

In addition to the traditional concrete and metal, you could also go with fiberglass or high-density polyethylene (HDPE) which is not only inexpensive but also very durable.

For an even sturdier tank, one can go for reinforced concrete or fiber-reinforced plastics.

Septic Tank Size

Size is another important difference between modern septic tanks and older ones.

In the 1970s, most septic tanks were 500-gallon tanks.

In fact, the precast tanks that were made around this time were all of the same 500-gallon tank size.

Back then, that was the size that was deemed sufficient for an onsite waste management system.

According to Compass, the average size of the American home has increased significantly both in square feet as well as in the number of family members.

For instance, a 1970s home was 2,080 square feet whereas houses built after 2010 have an average of 2392 square feet.

This increase in size necessitated an increase in septic tank size which is why most modern homes have a 1000-gallon septic tank.

Technology

Septic tanks that were installed in the 1970s didn’t have much for technology – they were merely concrete or metal tanks that were used as an onsite waste management system.

The septic system was as simple as it could get – just a tank, a drain field, and the piping.

 Today, however, we have all kinds of sophisticated technologies that have been added to make the management of tanks easier.

 For instance, most modern tanks have filters that help prevent clogging of the drain field.

You can also have an alarm in your septic tank that will warn you when your septic tank is due for a cleaning.

Additionally, it is now possible to install double-tank or triple-stank septic systems which were unheard of in the 1970s.

Installation

Technological advancements have made the installation of septic tanks easier.

 For instance, in the 1970s, precast tanks could be used but it was limited to metallic tanks.

Today, you can have a precast tank in any material – including concrete.

In fact, it is very rare to have a septic tank built on site as most are precast and shipped to your site for installation.

This coupled with other things like better tools and equipment has made the installation of septic tanks much easier for the modern-day home

The Bottom Line

If you are thinking of owning a home that was built in the 1970s, there is a good chance it will come with the original septic tank.

Here are a couple of things you may want to keep in mind as you prepare to take ownership of the new home:

• Old septic tanks are just as good – as long as the septic tank has no leaks, the system should be just fine and you do not need to reinstall it.

• It is not illegal to have an old septic system—i.e owning a home that has a septic tank that was installed in the 1970s is not illegal. The only caveat is: the septic tank has to be in good working condition. However, you cannot install an outdated septic system on a new property.

So, there you have it – everything you need to know about the 1970s septic system. Share your thoughts in the comments section.