Community Sewer Systems

The short answer is, “Yes.”

However, it’s not very common. While several apartment units might share a single large septic tank, they still each need enough lateral lines to treat their effluent. So, a single apartment building would need several acres of leach field. An apartment complex would need to devote over half the land to wastewater treatment.

Advanced wastewater systems are a better option for apartments outside the reach of sanitary sewers. Because they treat septic effluent in a biological reactor rather than in the ground, they can reduce the acreage needed for disposal.

Here’s an example of apartment complex wastewater treatment that works :

Aerial photo of an apartment complex with wastewater effluent drip field labeled to show size
Upon entering this apartment complex, you drive past the clubhouse and wind by a lush slope. Spoiler: it’s the wastewater drip field.

Here’s the satellite view for scale:

Satellite view of an apartment complex with wastewater drip field outlined.

If you’re making plans to develop property into apartments, give us a call. We can help you make the most of the space.

Wastewater systems in the US are sized based on the maximum number of gallons per day they can treat.

A 300-room hotel, for instance, might require a 50,000 gallon-per-day system. Depending on soil loading rate*, that system might need a 2 acre drip field for effluent disposal.

An installer walking inside a wastewater system drip field dosing tank.
Every component in our systems must account for design criteria.

Here are some factors that determine how many gallons per day your community septic or other wastewater system must be able to handle:

  • Capacity in gallons per day is determined by state and local design specifications.
  • These regulatory agencies calculate required treatment capacity in terms of maximum gallons used per person per day or maximum flow per bedroom per day, etc.
  • Commercial wastewater systems use more complex formulas that take their specific usage into account. The hotel mentioned above might need to account for 75 gallons per bed per day but might also have a restaurant and a bar attached for which another 12 gallons per seat per meal would have to be added.
  • Design criteria must also assume the level of pollution present within wastewater from different sources. Very dirty wastewater takes longer to treat which means systems must have higher capacity than what is released to give the system the time needed.

Here is an example of a design criteria matrix from an actual state regulatory agency:

An example design criteria table for wastewater system capacity in residential and commercial applications.
Design criteria differ based on locality.
  • Design criteria tables such as the one above provide a starting point to determine size, but in most cases, regulatory agencies grant variances based on actual flow and treatment level.
  • We at Aqua Tech will research the design criteria required for your project and budget around them. As the build gets closer, we reevaluate your treatment needs and work with civil engineers and regulatory authorities to ensure regulatory compliance without excess expense.

Bottom line: Use this table to get a rough estimate. When you’re ready, let’s talk and get more specific.


*Soils differ in how much moisture they can absorb per hour. Very dense soil might only be able to absorb one tenth of a gallon per square foot every hour while porous soil can absorb almost a full gallon per square foot. Soil absorption per hour is called its “loading rate.” The higher the loading rate the smaller the drip field needed.

Several places around the US are currently experiencing a construction boom and we’re delighted to be a part of it. Here’s a mixed use system that our engineers have just designed.

This system is designed to treat 37,000 gallons of wastewater per day.

This particular system was designed to treat residential and commercial wastewater at the same time. Notice that the effluent (outflow) discharges at ground level. This is a septic system with no leach field!

Here’s the secret:

This private wastewater treatment plant removes nearly all of the Biological Oxygen Demand (BOD), Total Suspended Solids (TSS), and Total Nitrogen (TN).

Got an enquiring mind? Here’s an overhead view of the same sewer system design:

Here’s what a similar system looks like in real life:

Wastewater treatment plant overhead view
A 3-tank in-ground system with a methanol doser and all-weather controls

Whether you’re an engineer or a real estate developer, we can help you put together a system to meet your needs. Just click the button below!