State Design Flow Library

Our Growing Design Flow Library

Most states in the US publish design flow charts to stipulate the capacity of wastewater systems. Here’s a list of residential and commercial design flow charts for new construction organized by state.

These documents have been downloaded from various regulatory agencies. Jurisdictions for any particular job will vary. Aqua Tech makes no certifications regarding the veracity, applicability, or relevance of the documents listed below.

Contact us for more on how to plan the wastewater component of your particular project:

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Advantages over septic:

  • Increased building density. They don’t require big drain fields on each lot.
  • Longer lasting. Land disposal through drip irrigation doesn’t become spent through built-up solids like septic leach fields.
  • Much better for the environment. Decentralized systems treat wastewater through accelerated natural processes, thereby eliminating water-borne pollution.

Advantages over municipal systems:

  • Sooo much cheaper! Decentralized systems reduce or eliminate the need for miles of large diameter pipe and lift stations.
  • No smell. Designed to be small and efficient, they treat so fast that there’s no detectable odor outside of a few feet from the system.
  • They facilitate development in growth areas without increasing tax burden or contributing to suburban sprawl.
  • They keep water in local aquifers rather than sending it downstream.

Talk to an expert!

(479) 530-7922

One of the biggest challenges to implementing comprehensive land use plans is how to accommodate new development in locally designated growth areas that do not have public sewers. Many rural and suburbanized towns in the US face this question.

They want to direct growth to the most suitable areas of town – near existing services, such as fire stations and schools, for example – but have no prospect of gaining access to public sewer lines. New development must rely on soils, usually on a lot by lot basis, to handle wastewater. The conventional wisdom says that means low densities of development, negating the effectiveness of a growth area. However, towns and counties without public sewer systems have options that they may not realize.

four tank wastewater system behind green metal fence

Additionally, watersheds in the United States reflect tremendous diversity of climatic conditions, geology, soils, and other factors that influence water flow, flora and fauna. There is equally great variation in historical experience, cultural expression, institutional arrangements, laws, policies and attitudes. With regards to wastewater issues, it would be a mistake to impose a standard model from the federal level to address the needs on a local level. Correspondingly, centralized
sewer systems are aging, frequently underfunded with respect to replacement costs and expensive to maintain. In addition, centralized sewer strategies are increasingly challenged by environmental and social considerations such as inter-basin transfer issues, aquifer depletion, nutrient loading and urban sprawl.

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Decentralized wastewater management has the potential to be the catalyst for the re-creation of our institutions, to support a new agenda, and for rapidly building a flexible infrastructure to sustain the integrity of the natural systems that are essential to a healthy economy.

Tom Bartlett – founder and Ceo of aqua Tech

The new emerging civic agenda of smart growth, community preservation, open space planning, ecologically sound economic development, resource conservation, and watershed management demands that we rethink what constitutes assets and liabilities. With a capacity of roughly 200,000 gallons per day, these off-grid plants can be constructed at a cost of well under $3,000 per home. These are economic, environmental and quality of life issues and they do not lend themselves to single purpose solutions. They require local community based consideration within the context of flexible multipurpose planning.

Statistics have shown us that within the U.S., twenty-five percent of existing residential real estate and forty-seven percent of new construction are served by onsite treatment systems. Many of these systems are acknowledged to be inadequate with respect to soil absorption, nutrient removal, resource protection and public health. Ironically, despite these statistics and EPA policy changes, most regulatory codes as well as most municipal and commercial planning continue to consider onsite systems to be temporary solutions awaiting a centralized sewer hookup.

male constructor drawing draft on paper roll
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Looking beyond the traditional assumption that wastewater is simply a matter of safe disposal and the public health; the real contemporary wastewater issues are the economic and environmental issues in which the public has a primary interest:

  1. Drinking water quality
  2. Deterioration of recreational water resources and other natural systems services
  3. Property Values
  4. Economic development in small and rural communities
  5. Urban sprawl

Beyond just disposal, decentralized wastewater management has the potential to contribute to the formation of an infrastructure to sustain watershed integrity. Decentralized wastewater treatment serves the “watershed agenda” and the principles of “community preservation” and “sustainable development.”

When approaches to the larger wastewater issues are successfully accomplished everyone benefits:

  1. Local communities win open space zoning, water quality and supply protection, increased development capacity and an expanding tax base.
  2. Natural systems are sustained through prudent zoning and reduction of non-point pollution.
  3. Developers win additional lots for development and higher margins typically associated with conservation subdivision design and municipal infrastructure.
  4. Regulatory agencies win because they gain partners in compliance management such as the municipality and perhaps a watershed authority.
  5. Citizens and homeowners win because property values are enhanced as schools, healthcare providers, and retail outlets crop up around the new infrastructure which decentralized systems provide.
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There are no major obstacles to a decentralized infrastructure for wastewater treatment.

New technologies in a properly managed context provide the opportunity for a land based watershed initiative that could significantly reduce small flow point source discharges such as those associated with onsite treatment systems. A decentralized wastewater management infrastructure should include:

  1. Clustered, performance-based, decentralized wastewater management systems
  2. Industrial & commercial pretreatment prior to discharge to existing sewage treatment systems
  3. Wastewater reuse systems

Estimates suggest that this infrastructure is achievable with technologies that require 50% to 70% less space with corresponding reductions in cost of 40% to 50%. For citizens in small and rural communities these reductions represent opportunities to preserve water quality, to stimulate economic development and job formation and to restore property values. Essentially, we are shifting from large sewage collection systems and centralized treatment plants to small and decentralized management systems. Keep in mind also that this is not an alternative to centralized sewer. Rather, it is a complimentary adjunct to the existing infrastructure.

Moreover, the decentralized solution is coming from local community and watershed needs. It is not coming from the bureaucracy. It is essentially good old bottom-up American pragmatism. It is important, therefore, that the general population becomes informed about the benefits of the decentralized approach. We must find a suitable mechanism to accelerate the progress to support watershed management. If we can not find such a mechanism, we run the risk of letting the limited existing strategies (centralized and onsite) dominate the next 20 to 30 year cycle.

Same Destination – Different Paths

With every project being considered for an Aqua Tech System, planners must consider many factors in the selection of an appropriate site specific wastewater collection system.

Such as:

  • Housing density and road frontage
  • Size of the project and wastewater volume to be conveyed
  • Topography and sensitive natural resources
  • Depth to bedrock or groundwater
  • Distance to the wastewater treatment and dispersal site
The Settling Tank getting a final inspection

During the design process of your system the following methods should be considered:

  • Conventional gravity systems (with lift stations as required)
  • Septic Tank Effluent Gravity (STEG) system (AKA small diameter gravity sewers)
  • Septic Tank Effluent Pump (STEP) pressure system
  • Grinder pump pressure sewer system
  • Vacuum

These collection or conveyance systems often represent the major portion of the total capital cost associated with any wastewater system, so careful consideration should be made to avoid extraneous expense while also ensuring reliability and environmental compliance.

Let us help you design a system that takes everything into account.

S.T.E.P. is short for Septic Tank Effluent Pump. Our S.T.E.P. system delivers influent to an Aqua Tech Systems treatment plant through small-diameter, pressurized pipe. This eliminates the need for costly gravity piping and even more costly lift stations. This approach significantly reduces a developer’s upfront infrastructure costs and allows them to phase/defer some expenses until lots are sold. S.T.E.P. also allows each home to positively contribute to wastewater treatment at the source; therefore both capital and maintenance costs can be distributed among homeowners.

In addition to lowering development costs, S.T.E.P. technology improves effluent quality by retaining most solids at the source, where they naturally degrade through anaerobic processes. The clarified effluent is then pumped to the next stage of the Aqua Tech system, where it undergoes further aerobic treatment for enhanced purification.

We put this Effluent Pump…

…into this Septic Tank (not to scale).

A more detailed view:

Here’s a video:

A video slideshow on the benefits of STEP Collection

Here’s how it looks when we’re done.

STEP tank installed

STEP to Treatment


The STEP Advantage

Reduced Cost – Smaller pumps and shallowly buried pressure pipes lead to lower
installation and operational costs compared to traditional gravity systems.
Improved Water Quality – The prescreening process in the septic tank sends less
solid waste to the treatment plant
No Manholes or Lift Stations – Eliminates the need for expensive and hard-tomaintain
lift stations. A Lift Station for a sub-division can cost up to $1 Million, and
even more for excavation, engineering, and electrical work.
Emergency Storage – Watertight tanks provide at least 24-hour emergency storage
on site.