Advanced Wastewater Treatment

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:

How Much Does a Sewage Treatment Plant Cost?

“How much does a sewage treatment plant cost?”

It depends…

One of the first questions we get asked, is “How much does a sewage treatment plant cost?” That’s a reasonable question. And we love answering it! That’s because our top-quality systems are also some of the least expensive on the market. Don’t believe us? Click the button below to get an estimate for your particular project and then shop around.

Every Aqua Tech system is custom designed around each project. Our sewage treatment plants must meet local design standards while serving the particularities of each application. Factors such as collection type, design flow, and disposal method all play into the system design. And the system design determines the price.

In asking, “How much does a sewage treatment plant cost,” it’s important to remember that size matters.

Wastewater treatment systems, like a lot of other products, are subject to the economy of scale. Price per gallon goes down as the system size goes up.

Like in the diagram, the effect is more pronounced as the system size gets smaller. A 2000 gallon per day system might cost 3x as much per gallon as a 20,000 gallon per day system which might cost 30% more per gallon than a 40,000 gallon per day system.

The economy of scale in this case means that smaller systems require the same planning, design, construction, installation and startup time as do the larger systems. So, if you ask, “How much does a sewage treatment plant cost?” We’ll first need to know, “How big?”

It’s also important to remember that not all sewage is created equal.

Commercial wastewater is typically higher strength than what comes out of your home. RV Parks, for instance can produce raw sewage with a BOD (biological oxygen demand) of nearly 1000 mg/L while concentrations in residential wastewater average around 250 mg/L. Higher strength wastewater requires more biofilm media, larger bioreactors, and bigger tanks to reach mandated effluent limits.

Location (location, location) affects wastewater system price.

Several local conditions such as fast perc rates, high water tables, high quality, or impaired waterways call for stringent treatment levels even for subsurface disposal.

The Chesapeake Bay for instance, has been designated by the EPA as an impaired waterway. That means wastewater discharge in its watershed must be treated to municipal wastewater treatment standards or better.

process flow diagram for an mbbr wastewater treatment plant treating to under 2.5 mg/L TN

This is a process flow diagram for a system to be installed in the Chesapeake Bay Watershed. It requires special appurtenances (add-ons) to ensure reduction of total nitrogen to under 2.5 mg/L.

process flow diagram for an mbbr wastewater treatment plant treating to under 2.5 mg/L TN

That’s a heckuva lot of reduction for a system discharging subsurface.

Sometimes location affects the way treated effluent must be disposed.

The soil in the eastern two-third of Texas, for instance, absorbs very poorly. TCEQ (Texas Commision on Environmental Quality) consequently mandates a soil application rate (SAR) of no more than .1 gallons per square foot per day for subsurface drip disposal systems. That means drip disposal outside the crosshatched counties on this map can cost three times as much as the national average.

TCEQ subsurface disposal guidance map.

Disposal method affects how much a sewage treatment plant will cost.

Aqua Tech’s wastewater treatment technology is so advanced that we also sell surface water discharge systems. With surface water discharge you can do away with a disposal system altogether. That means the system will need to treat to a higher level and include disinfection. But even with those additions, surface water discharge systems price out around 10% less than subsurface disposal systems in most cases.

wastewater treatment tank with integrated controls
The Southside School wastewater treatment reactor with UV disinfector.

Getting there can be half the savings.

The cost of a sewage treatment plant is only part of the overall cost of developing your sewer infrastructure. Sanitary sewers needed to convey the wastewater to the system can cost significantly more than the treatment and disposal systems together. Many Aqua Tech customers have found they can save a ton of money up front and over the long run with STEP Collection. And because STEP Collection eliminates the need for a large settling tank at the treatment works, it can save you money on the treatment system as well.

There’s no fast way to accurately answer, “How much does a sewage treatment plant cost.”

But we don’t mind doing the work to put a free estimate together. Just fill out and submit this form!

Whitepaper for BioTank biological reactor in wastewater treatment.

BioTank, Aqua Tech’s biological reactor, is the best value in wastewater treatment for residential and commercial development as well as for small to midsized communities. The following product details demonstrate BioTank’s durability, versatility, and efficiency.

Moving bed biological reactor with transparent background
A BioTank hot off the manufacturer’s floor

Aqua Tech’s BioTank bioreactors range in capacity from 160 GPD to 80,000 GPD. They can be installed modularly to build systems with a capacity over 1 million GPD.

Our stainless-steel package systems operate with minimal maintenance for decades. They provide a timely and cost-effective alternative to site-built treatment facilities.


The BioTank is a factory-made, multi-chamber aeration tank made of stainless steel AISI-304. It is equipped with fixed and floating media and an aeration system comprised of an air compressor, snorkel, regulator valves, hoses, and oxygen diffusers.

The various chambers facilitate the growth of stage-specific microbes ensuring progressively higher levels of treatment through each chamber.

AISI-304 stainless steel construction allows for above ground and inground installation.

State of the art media provides maximum biofilm surface area which results in smaller bioreactors that treat up to municipal standards.

The aeration system ensures optimal oxygen conditions for advanced biological wastewater treatment.

Biological Reactor Applications in Wastewater Treatment

As a biological reactor, BioTank isn’t suitable for treating water from sources with high concentrations of chemical contaminants such as storm water, drinking water treatment centers, boiler houses or factories.

The BioTank treated effluent quality allows its safe discharge into the environment or reuse for irrigation or other technical needs.

The BioTank can be designed to meet any effluent standards including advanced treatment required for sensitive areas.

A pristine waterfall at an RV and cabin resort with over 200 units serviced by a biological wastewater reactor
A pristine waterfall at an RV and cabin resort with over 200 units serviced by one little BioTank.

General Provisions

Installation of an Aqua Tech system with BioTank biological reactor will require:

  • Site prep including a poured concrete pad for the BioTank, drainage areas and access roads
  • Dedicated electrical power supply (usually 3-phase)
  • Specialized onsite treatment systems for all local sources of wastewaters which do not correspond to the BioTank application terms

Wastewater should be primarily treated prior to be pumped to the BioTank. The primary treatment should include mechanical treatment (coarse solids and grit removal), FOG (fats, oils and greases) removal, wastewater settling and flowrate equalization.*

Process Specifications

FOG (fats, oils, and grease) Removal

FOG level should be constantly monitored, preferably by means of sensors.*

Amount of FOG enter the BioTank should not exceed 50 mg/l.

If FOG concentration is permanently higher than 50 mg/l in any of local discharges, then it is necessary to apply specially selected biopreparation for FOG decomposition, for example, BioEaseTM4210.

If FOG concentration exceeds 100 mg/l, then it is necessary to build a local grease trap and use the biopreparation for FOG degradation.

Overhead diagram of a wastewater treatment system with methanol doser
Overhead diagram of a wastewater treatment system for mixed-use featuring two BioTanks operating in tandem.

Coarse Solids Removal

The feed pumps should be protected from coarse solids present in wastewater. Depending on a primary treatment technology Aqua Tech Systems offers a solution for the removal of coarse solids.

Grit Removal

Wastewater usually contains certain amount of grit and other mineral substances, which should be removed before wastewater feeding to the BioTank.

Primary Settling

Suspended solids (SS) concentration limit for biological treatment based on the biofilm process is 105 mg/l. As raw wastewater usually has higher SS content (> 105 mg/l), primary settling should be introduced.

Primary Sludge Accumulation and Digestion

Primary sludge volume and odor are significantly reduced through the addition of a biopreparation such as Bacti-Bio 9500.

The sludge level should be constantly monitored by means of an automatic sludge level sensor or manual Sludge Judge device. Sludge removal and disposal should be handled by a certified contractor as needed (usually every 3-5 years).

Flowrate Equalization and Feeding

Aqua Tech installs flowrate equalization systems to minimize BioTank size and maximize performance.

Wastewater equalization enhances biological treatment by minimizing shock loads, diluting inhibiting substances, and stabilizing pH.

The assumed wastewater feeding duration to the BioTank is at least 18 hours/day.

The assumed feeding volume is:

v = Qday / 18, m3/hour, where Qday is wastewater amount per day

Aqua Tech Systems provides necessary settling-digestion and wastewater flowrate equalization tanks of the required volumes which are plastic or ferro-concrete.

Installation of precast concrete tank for wastewater settling and equalization
A combination settling and equalization tank being installed in Alabama

Phosphorus Removal

If required, phosphorus is removed during primary settling through the addition of coagulant.

Biofilm cannot remove more than 1-1.5 mg/l of phosphorus. The formed biocenosis of the biofilm, being in a state of dynamic equilibrium, does not produce biomass and, accordingly, does not consume phosphorus.

Wastewater processing with coagulant ensures efficient organics reduction and reduces the phosphorus below 1.0 mg/l.

Where required, Aqua Tech provides a coagulant dosing apparatus at the primary treatment step.

Biological Treatment

Process Characteristics

BioTank’s biological wastewater treatment process is based on the biofilm technology. Biofilm is a dense community of attached-growth microorganisms living on specially designed plastic media. The surface of the biofilm treats wastewater by absorbing and oxidizing pollutants. Multiple biozones within the layers of the biofilm create a self-cleaning, self-sustaining ecosystem. The biofilm develops the microorganism diversity necessary for maximum treatment in each application. Due to efficient ecosystem development in the BioTank there is no excess biomass growth.


Incoming organics are sequentially oxidized by isolated biocenoses of microorganisms living on media retained within the borders of each aeration chamber. The media is submerged in water.

Oxygen supply and mixing are provided by aeration.

Due to change of oxidation rate at each process stage – from high on the first stage to low on the last stage – the loads on biocenoses and water saprobity vary from high to low accordingly.

In response to changing environmental conditions and amount of dissolved oxygen, the treatment process occurs as follows:

  • Stage One – sorption and oxidation of dissolved organic matter, adsorption of suspended solids and colloids and hydrolysis (fermentation) of suspended solids and colloids
  • Stage Two – sorption and oxidation of dissolved organics,
  • Stage Three – biofiltration (biosorption)
process flow wastewater package plant diagram for commercial sewage treatment system
Process flow diagram for a commercial application with heavily contaminated influent.

Oxygen Conditions

Oxygen supply is provided by aeration. The oxygen mode is a function of organic load, biofilm density and thickness, and wastewater temperature.

The required amount of dissolved oxygen for each process stage should be optimized and adjusted according to the Aqua Tech Systems recommendations at start-up and follow-up analysis.


The Biotank’s biofilm process configuration creates conditions for simultaneous nitrification and denitrification.

The corresponding environment allows formation of layered biocenosis. The layers are determined by the amount oxygen diffusion into the biofilm.

The biofilm surface is the aerobic layer which creates conditions for heterotrophic microorganisms to partially oxidize and reduce ammonium along with oxidation of organic matter.

The internal mass of the biofilm is the anaerobic layer that creates conditions for development, growth and accumulation of specific autotrophic microorganisms (ANAMMOX) which oxidize and reduce the main part of incoming ammonium.

Biofiltration (Biosorption)

Biofiltration or biosorption occurs in the BioTank on a static media.

In low load conditions bacteria release a significant amount of exopolymers capable to capture and retain solids during contact. In turn, solid substances captured by the biofilm (bacteria, organic matter) serve as a food for predators and detritophages that results in reduction of suspended solids amount.

It should be noted here that bacteria and predators create symbiotic relationship after a number of successions, under which predators regulate their quantitative and qualitative composition in a strict accordance with incoming food amount.

Also the significant input in clarification comes from attached stalked ciliates (Peritrichia). The peritrichs provide themselves with food by filtering large amounts of water. One individual is able to consume up to 30,000 bacteria per hour. This way peritrichia provide a high degree of biological disinfection, destroying pathogenic microorganisms.

Low organic load and high amount of dissolved oxygen in the biofilter provide partial ammonium removal.

Ammonium bio-oxidation is carried out in two stages, by two types of chemoautotrophic bacteria:

2NH4+ + 3O2Nitrosomonas = 2NO2- + 2H2O+4H+

2NO2- + O2Nitrobacter = 2NO3

man at advanced wastewater treatment system testing effluent levels


Formation of the biofilm occurs spontaneously based on the set and maintained level of dissolved oxygen in each chamber. The biofilm reaches dynamic equilibrium as it develops through the initial operating period. Once this happens treatment process performance meets the project requirements.

Under conditions of actual loadings correspondent to the design specifications biocenoses fully mature:

  • For “B” bio-oxidation process – within four weeks
  • For “N” bio-oxidation and nitrification process – within one year.

The actual treatment efficiency should be at least 95.99% of the calculated one.

If necessary, the achievement of treatment quality for the process “N” can be accelerated by the use of methanol. Methanol provides an additional food source for heterotrophs which thereby multiplying their population. Due to lack of oxygen, heterotrophic microorganisms use oxygen from nitrates, thus reducing oxidized nitrogen. In this case it is possible to reach at least 90% of all required parameters within 60 days from start-up.

*Sold and supported by Aqua Tech Systems.

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.

Secondary wastewater treatment uses natural biological processes to protect the environment from contaminants in sewage.

Wastewater poses several threats to the environment. Microorganisms use oxygen to digest the organic matter in sewage. The rate of this digestion can be measured as Biological Oxygen Demand (BOD). Water with high BOD can deplete dissolved oxygen in waterways thereby suffocating wildlife.

septic tank cutaway
A common septic tank design

Septic tanks use gravity to settle out around 70% of wastewater solids. This settling is called “primary treatment.” The other 30% of solids remain in the wastewater and flow out into the environment. We measure this component of wastewater as total suspended solids (TSS). Primary treatment achieves only a 30% reduction in BOD. While better than nothing, septic systems discharge contaminated wastewater into the environment via a drain field. Larger flows, higher strength wastewater, or poor site conditions can require further treatment to protect the environment.

Enter the secondary wastewater treatment system.

While technologies vary, all secondary wastewater treatment systems use oxygen to accelerate the bacterial consumption of organics. Aqua Tech recommends and sells MBBR (moving bed biofilm reactors). MBBR technology is the most recent innovation in wastewater treatment systems. These biological reactors can treat to a high standard with virtually no operational time or recurring costs. And our MBBR’s are the best on the market.

All MBBR’s host a bacterial slime layer on a plastic media of some kind. Wastewater treatment takes place where that slime layer contacts the contaminated sewer water.

the bacterial slime or “biofilm” is actually three layers each hosting a different type of bacteria

Systems with more contact area treat more efficiently. Our MBBR’s use ultra-high density biofilm media to host up to 5000 M2 of contact area for every 1 M3 of reactor space. That means our treatment reactors can do a ton of work in very little space. And smaller reactors are cheaper reactors.

7000 gallons per day of treatment capacity in this tiny box!

Through secondary treatment BOD and TSS are normally reduced by at least 85%. Our systems can reduce them by 99%.

But BOD and TSS aren’t the only potential environmental hazards in wastewater.

Nutrients like nitrogen and phosphorus can choke waterways and pollute drinking water. Nutrient reduction in wastewater is called “tertiary treatment.”

Our high-density biofilm media performs tertiary treatment simultaneous with secondary treatment. A recently discovered species of bacteria metabolizes the most basic nitrogen compounds, into nitrogen and oxygen gas. The Annamox bacteria can’t grow in every kind of wastewater technology, though. Their long lifecycle requires a protected habitat for them to grow and reproduce in sufficient numbers to mitigate total nitrogen. Our proprietary “biochips” provide protected pockets for Annamox to live and do their work. After about a year, our BioTank reactors can produce effluent discharge under 10 mg/L in total nitrogen with only oxygen.

infographic of nitrification and denitrification in wastewater
Conversion of ammonia to nitrate and nitrate to nitrogen gas in wastewater.

So our secondary wastewater treatment systems really provide tertiary results.

Wanna know more about wastewater or how we can take care of it for you?

What does Advanced Wastewater Treatment involve?

Short answer:

“Advanced” doesn’t necessarily imply a particular type of technology so much as it refers to a degree of treatment. If the effluent leaving a system meets stringent criteria it’s said to have undergone advanced treatment.

Longer answer – Advanced treatment systems:

  • Use new technologies to accelerate biological consumption of organic contaminants in wastewater.
  • Remove toxic ammonia through nitrification.
  • Mitigate eutrophication of waterways by reducing nitrogen and phosphorus through Biological Nutrient Removal (BNR).
  • Sometimes introduce coagulants which settle nutrients and suspended solids through flocculation.
  • Occasionally feature chlorinators or UV arrays to sanitize effluent.
  • Rarely apply carbon filters to remove residual contaminants through adsorption.

Aqua Tech can design and build an advanced treatment system for nearly any situation.

Drip irrigation systems are an efficient and proven technology many communities use to recycle and dispose of treated wastewater. The effluent is applied to the soil slowly and uniformly from a network of narrow tubing, placed in the ground at shallow depths of 6 to 12 inches in the plant root zone.

Because water is such a precious commodity, recycling wastewater can have both economic and environmental benefits for communities. Reusing wastewater to irrigate land can help protect surface water resources by preventing pollution and by conserving potable water for other uses. This is particularly important where community water supply sources rely on wells. The more water that is pumped from wells and discharged as effluent into a stream or other surface water, the less will be available to recharge aquifer or groundwater sources upon which future well water supplies rely.

Another benefit of applying wastewater to the land is that the soil provides additional treatment through naturally occurring physical, biological and chemical processes. Irrigating with wastewater also adds nutrients and minerals to soil that are good for plants and it helps to recharge valuable groundwater resources.

Residential developments with low building density required by septic drain fields contribute to an undesirable sprawl and limit land available for playgrounds, hiking trails, and other open space amenities. Spray systems, while superior to septic, can also limit land use since they produce aerosols that require large buffer zones.

Community sewers that use drip irrigation consolidate undersoil treatment into one region of the subdivision. This region can provide a visually appealing common area for the development. Achieving higher land use densities with desirable open spaces are important and shared goals of land use planners, environmentalists, and developers alike.

Soil reuse systems require less monitoring and thus lower operating costs when compared to surface discharge.

Additionally, subsurface discharge expedites the acquisition of state and county permits by addressing potential concerns of downstream property owners removing any reason for them to contest approval.

Beneficial reuse through drip irrigation is just another way we’re equipping responsible growth. Click the button below to see how we can equip you.
architecture backyard brickwalls chimney
Photo by Pixabay on

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.

blue and gray concrete house with attic during twilight
Photo by Binyamin Mellish on

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
Photo by Andrea Piacquadio on

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.
clouds country countryside dirt road
Photo by Pixabay on

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.

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!

The BioTank is at the heart of the Aqua Tech System

The BioTank uses floating and fixed film processes in which microorganisms attach themselves to a  highly permeable media that is submerged in the wastewater. This allows for the absorption of organic and inorganic matter into the slime layer where treatment is realized. Designed properly, this filter is self-purging.

Hydraulic dosing and secondary sludge airlift pump systems are set at pre-determined rates to minimize maintenance and enhance treatment. The self-purging biological filter is designed by Aqua Tech Systems to accommodate influent characteristics and achieve effluent requirements. Oxygen is introduced to the system via an oil-less compressor and membrane aeration equipment.

Wastewater is pumped from the influent pump chamber to mechanical equipment or directly into the first baffled compartment of the BioTank. Alternatively, primarily settled
or prescreened wastewater is pumped from an equalization basin to the BioTank. Wastewater flows by gravity through each treatment compartment of the BioTank and effluent is discharged over a weir.

As flow enters each aerobic compartment dissolved oxygen is transferred to the wastewater via compressor and membrane aeration module. Each compartment has an independent and fully adjustable air regulation valve. In the aerobic modules the
compressor acts as a mixer to enhance treatment and prevent the short-circuiting of wastewater through the plant.

In the BioTank, the organic material in the wastewater is reduced by a population of microorganisms that attach to the filter media and form a biological slime layer. In the outer portion of the slime layer treatment is accomplished by aerobic microorganisms. As the microorganisms multiply the biological film thickens and diffused oxygen is consumed before penetrating the full depth of the slime layer. Consequently the film develops aerobic, anoxic and anaerobic zones.

Absent oxygen and a sufficient external organic source for all cell carbon the microorganisms near the media surface lose their ability to cling to the media. The wastewater flowing over the media washes the slime layer off the media and a new slime layer begins to form. The process of losing the slime layer is called “sloughing” and it is primarily a function of organic and hydraulic loading on the filter. This natural process allows a properly designed media bed to be self-purging and maintenance free.

Any excess sloughed biomass is transferred with the wastewater flow to the final clarifier as sludge. These secondary sludges are periodically pumped back to the primary tank or sludge holding tank for eventual removal or further treatment.

The BioTank treatment plants may also be supplied with bar racks or screens, grit chambers, flow meters, chemical dosing equipment, UV disinfection modules and sludge dewatering systems.

To put the BioTank to work for you, click the button below to schedule a consult.

“STEP” stands for Septic Tank Effluent Pump

We put this Effluent Pump…

…into this Septic Tank (not to scale).

Here’s a video:

A video slideshow on the benefits of STEP Collection

Here are the gory details:

Technical schematics for STEP collection

Here’s how it looks when we’re done.

STEP tank installed

Our STEP system creates a pressurized, small pipe influent delivery structure to the treatment plant which eliminates the need for the expensive piping and lift stations that gravity systems require. This means that developers can cut their cost as well as defer some of that reduced cost of the community wastewater system until lots are sold. Since each home shoulders some of the load associated with wastewater treatment, the initial cost and maintenance can be distributed to the homeowners as well.

Beyond reducing development cost, STEP technology further enhances effluent water quality by leaving the majority of the solids at the point of origin where they can degrade through anaerobic processes. The effluent leaving the tank at the home then becomes the influent which the next component in the Aqua Tech system will treat through aerobic processes.

STEP Over to Treatment

A process flow diagram for a 25000 gallon per day wastewater treatment system using STEP Collection
After STEP Collection, the effluent travels under low pressure to a system like this.