Decentralized Sewer - Operator Stories for Engineers - Collection Systems Options

In my career, I had to learn the hard way. I didn’t ask the right questions, didn’t ask the right people, and sometimes didn’t listen to sound advice. Now having accumulated 20 years’ worth of stories, I hope to pass along learning from my time operating wastewater systems. 

Wastewater collection systems are simple from an engineering perspective. Let gravity work for you and pump when you must. The usual approach is to design a wastewater treatment system with a bit of space for future flow and modest infiltration and inflow (I/I), but in practice, this leads to operators fearing storm clouds and cursing the design engineer. 

I can’t tell the number of times I have seen a small system (25-200 homes) with peaking factors of 5 -15 times average daily flow during rain events. This happens so quickly due to broken clean out caps, bad joints, illegal roof drains, illegal sump pumps, offset manhole rings, manholes in a ditch—I can go on and on. Smaller developments rarely benefit from gravity sewer due to the inevitable I/I and ongoing maintenance cost to line, rehab, test, and hope you find the big leak.  

After a few years watching CCTV sewer videos, I firmly believe low-pressure sewer is an obvious choice for development. But not all low-pressure sewer systems are created equal. Not by a long shot. A poorly selected low-pressure sewer creates a different kind of problem, one I call “The Time Bomb.”

Nearly all low-pressure sewer systems have little to non-existent I/I since the system is closed apart from vacuum systems. Less I/I allows for smaller wastewater treatment plant design and ease of operation moving forward.

There are three common options for low-pressure sewer: grinder stations, STEP, and vacuum. 

• Grinder Stations: In my career I’ve managed small to large wastewater collection systems. One of the most difficult systems consisted of over 1,000 grinder pump stations. The stations housed one centrifugal pump per house and fed to a low-pressure sewer network. The most common feeling associated with that system was anxiety. The way grinder pump stations fail is seemingly random. A station will alarm and the homeowner calls in seeing the red light flashing on top of the box in the backyard. At that point the race begins. You dispatch someone immediately because most, if not all, grinder stations have very limited emergency storage, and the most common alarm call is due to high level. This simple fact causes the operator to always be reacting, not preventative. A quick note on grinders in general: when a resident knows they have a “grinder pump” some people take this as license to flush crazy things down the drain. I’ve seen t-shirts, diapers, and all manner of unmentionable items. The station is designed to “grind it up” and send it on. If the grinder is successful, the downstream wastewater plant now must deal with tiny floating bits of inorganic material in the headworks (which requires fine screening to remove—not common in package plants. Or the tiny torn bits of flushable wipes coagulate with grease in the equalization basin and float to the top, creating a grease cap derived in your operators’ nightmares. This material must be sucked off, and sent away in a dumpster with all the smells you would expect of putrid grease laden … I digress. In short, grinder stations are Time Bombs. You never know when they will blow and that makes the life of your operator much worse, since it likely can’t wait till the morning or Monday. 

• Vacuum System: I operated a vacuum system on the coast. Each house had a vacuum pit that ejected waste to the central wastewater treatment plant. The theory of vacuum is neat (as an engineer) but in practice it is horrible to operate. For example—I got a call at 10 pm on a Thursday from an automated alarm system. The alarm is for low system vacuum. This means soon the entire vacuum system will not be strong enough to pull wastewater from ejector pits causing sewer backups across the ENTIRE SYSTEM. I call another operator and we race to the site. Once there, it is dark and we start walking and open each ejector pit and press a button to see if we hear the leak. … I’m not sure if that sunk in, the operator must find the leak by listening. House by house, street by street, until you find the faint hiss of a leak and replace the component in the ejector pit. NEVER install a vacuum system. They are operationally wrought with the need for overtime since the best time to find a leak is when it is quiet or at night. Side note: homeowners are a bit wary of anyone walking around the neighborhood past 10 PM with a flashlight, hammer, and large screwdriver. Safety first!  

• STEP: Septic Tank Effluent Sewer or STEP is by far the best option for operation and maintenance. I would also argue for the design of downstream wastewater treatment systems. First, from the operator perspective, every STEP tank is a septic tank that pumps clarifier liquid to the treatment plant. Since the raw wastewater must settle out solids and additionally float Fats, Oil, and Grease (FOG), the pump in each STEP is a liquid only pump with a warranty over 5-10 years. Not a grinder pump that comes with a one-year warranty that you fully expect to fail unexpectedly. That is the foundational difference. The “Time Bomb” problem is solved. If a STEP pump fails, this is rare, you have real storage so you can respond on Monday or the next day. No need to rush out so you don’t backup the basement. Secondly, the FOG and unmentionable items found in wastewater stay in the septic tank. This means the homeowner has accountability. If they like to flush diapers, that is fine, since they just build up in the septic tank until you pump it out once every 3-5 years. Finally, the wastewater strength (BOD5) is reduced by up to 50%. This means the downstream wastewater treatment plant can be sized for a smaller influent load and therefore, be smaller. Also, unlike the grinder station scenario, the need for costly headworks is removed since grit and solids are trapped in each septic tank. 

For large systems, gravity sewer will be the most cost effective due to the economy of scale, but for residential/commercial developments, the case for STEP sewer as the preferred option for low-pressure sewer is obvious. Building systems with reliability in mind, along with the operator who will maintain the system is the engineer’s responsibility. I hope this helps you make the best decision possible moving forward. 

Colt Janes, PE
Project Engineer
Wastewater Operator

Surface Spray Irrigation Solution for NC poultry processor

This large poultry processor in NC needed a wastewater system upgrade. We built custom valve boxes in fiberglass shells, provided a telemetry enabled Orenco TCOM control panel to control and record their discharge pumps, and helped the client identify ways to make the operations and maintenance of their system more efficient.

AQWA provided the telemetry enabled Orenco TCOM control panel, custom built valve boxes, and technical support on the design, installation and operation of the system.

Expedited Review - 610 standards, engineered septics, alternative septics

There are a few permitting paths in South Carolina that you may have heard of: Expedited review, 610 standard engineered system, and a DHEC septic permit.

In both instances, the local DHEC or Environmental Health Department is bypassed for the initial soils review and permitting process. It is not uncommon for these local health agencies to be up to 12 weeks behind on soil evaluations for new septic system permits. In many instances, a property owner may wait all this time and still be turned down for a septic permit due to soil or site limitations that will require a soil classifier and/or an engineer to be hired.

In South Carolina, when a septic system is designed and permitted privately, this process is referred to as expedited review or the 610 standard. A developer can hire a soil classifier directly who can come out and provide a quick answer on how many lots a piece of raw land may support and the size and location of the drain field. After this soils report is completed, a “conventional” DHEC permit may be applied for using the private soil classifier’s report.

Alternatively, a 610 standard permit may be pursued wherein a SC licensed Professional Engineer would take the soils report that the soil classifier produced and design a system that creates the highest and best use for the lot. This could be single family homes, a hotel, restaurants, retail, or a 100 home subdivision.

Oftentimes, the DHEC created site plan and permit may not make the best use of the property due to the equipment and design constraints they are under. For example, an engineered system permit may produce a permit that has a smaller drain field footprint than the DHEC proposal which allows for more bedrooms, a pool, a garage etc.

The basic process if you are going through this process is as follows:

• Determine your project’s goals, number of bedrooms, home location, number of lots desired or other parameters that are important to you

• A SC licensed soil classifier performs a soil assessment with the goal of supporting your project’s goals

• A SC licensed professional engineer designs a system in accordance with DHEC rules based on the soil classifiers report

Oftentimes, you may hire an engineer who specializes in onsite wastewater permitting and they will take care of ordering the soils report as part of their scope of work.

We work with a great set of engineers and soil classifiers in the great state of South Carolina. Reach out to us today, and we can connect you with someone in your area who can help you through the process. Send an email to info@aqwa.net for more information.

New Case Study from Orenco - Pinebrook, NY

A new case study from Orenco highlights Advantex’s superior reliability and treatment efficacy for small flows compared to other treatment technologies like rotating biological contactors and activated sludge systems.

View the complete case study through this link.

Design Parameters

• 132 residential connections

• 15,000 gpd average

• 60,000 gpd maximum flow

NPDES Permit Limits

• 5 mg/L cBOD

• 10 mg/L TSS

• .93 mg/L NH3-N (summer)

• 1.3 mg/L NH3-N (winter)

Effluent Quality

• 2 mg/L CBOD

• .5 mg/L TSS

• .24 mg/L NH3-N

Equipment Used

• (2) 15,000-gallon Pre-anoxic

• (6) AX MAX units in (4) in Stage1 (2) in Stage2

• UV Disinfection

Surface discharge to a tributary of the Hudson River.

The AX MAX is the perfect tool to help developers of small communities deliver quality wastewater treatment in an affordable, reliable, sustainable package.

Is sewer really better for the environment than septic?

Take a look at this recent video by AQWA highlighting some misconceptions that people commonly hold about sewer vs septic.

STEP vs Grinder

Do you know what the difference between a STEP and Grinder pressure sewer system is?

Click this link (STEP vs Grinder) to watch a video and get a brief introduction to the differences. Once you’re finished, if you are still wondering if a STEP or Grinder is right for your situation, leave a comment below or give us a call at 252-243-7693 or email us at info@aqwa.net

Private Lift Stations - What is the best way to connect to sewer?

Have you been told you need a private lift station in order to connect to sewer?

There are a few different ways you could go about it. There are some dirt cheap options that have no emergency storage capacity and are a back up in the house waiting to happen.

I recently spoke to an engineer who owned a rental house in Myrtle Beach. Just a normal rental, not a vacation rental. That house had a private lift station serving it that pumped up to the nearby sewer line. I was telling him about our AQWASTEP package and he thought it was pretty cool. I told him roughly what it cost and he said “that’s more than I paid for what I have.” I asked a few follow up questions and started telling him about some of the benefits of our AQWASTEP.

10 year pump warranty, with pumps that last 15 to 20 years. He had replaced his grinder pump 3 times in a 15 years period.

24 hours or more of emergency storage volume - his system had backed up into his house all 3 times that the pump failed.

AQWASTEP uses pumps that are lightweight, easy-to-remove and inexpensive compared to grinders. Grinder pumps can easily weight more than 50+ lbs and generally cost significantly more than high head turbine pumps like we use.

So at the end of our conversation it was pretty clear to him that saving a few dollars up front had actually cost him many thousands of dollars, 3 big messes, and unhappy renters.

AQWASTEP is an easy way to connect to sewer in 90%+ of situations…high head pumps handle most elevation curves. 5 gallons per minute at 225 feet of TDH (total dynamic head.) If your situation is unique we can help you pick the right pump for your application, but the vast majority of projects don’t need more than 225 feet of elevation head.

AQWASTEP arrives pre-assembled, pre-wired, ready to be installed in the ground. The only thing left for you to do is mount the control panel and have your electrician supply power to it. We provide 50 feet of flex conduit with wiring pre-run in our standard package to make things even more simple.

Check out this short video that might help highlight a few of your decision points. STEP vs Grinders

Reach out to us at 252-245-7693 or info@aqwa.net for more information.

How to split a lake lot...

AQWA has worked with property owners, soil classifiers, and engineers numerous times over on waterfront properties. Everyone wants to live on the water and demand for waterfront property seems to be increasing all the time, but guess what, no one is making any more of it.

Or are they?

If I told you that you can take a 1 acre lake lot and turn it into two or three lots, wouldn’t you want to know how?

One project we worked on, we were able to help the developer go from 7 lake front lots to 17 lake front lots. That was a net change of almost $6 million dollars in real estate value.

Oftentimes the number one constraint of how small you can make a lake lot is the septic system.

In many areas, a 1 acre lot may have been the minimum lot size to make a 4 bedroom septic system work when the lot was originally platted.

Now a days we could turn that 1 acre lot into two or even three (4) bedroom lots.

That creates huge value for the property owner, as well as creating opportunity for more people to enjoy lakefront living. The way we go about it also creates better results for lake water quality and the environment.

Reach out to AQWA to find out how we can help you achieve the highest and best value for your lake front property. 252-243-7693 info@aqwa.net

Virginia AOSS - What is it? and other definitions in Virginia wastewater

Are you wondering what exactly an AOSS is in Virginia onsite wastewater parlance? You are not alone.

In the last 12 months or so, AQWA has really started pressing into the Virginia commercial and community decentralized wastewater world. It is amazing how much wastewater lingo varies from state to state.

Some of the common words used in the Virginia on-site world aren’t found elsewhere. Words such as: Mass drainfield, AOSS, (have to be careful about auto-correct with that one), TL-3, TL-2, TL-1, groundwater dilution, etc etc.

Below are the definitions I found for a few of these items while searching through the Virginia Administrative Code. These definitions are relevant anytime you are considering the best approach to tackling an onsite wastewater treatment and dispersal system for more than one home or business.

"Alternative onsite sewage system," "AOSS," or "alternative onsite system" means a treatment works that is not a conventional onsite sewage system and does not result in a point source discharge.

"Large AOSS" means an AOSS that serves more than three attached or detached single-family residences with a combined average daily sewage flow greater than 1,000 GPD or a structure with an average daily sewage flow in excess of 1,000 GPD.

"Small AOSS" means an AOSS that serves no more than three attached or detached single-family residences with a combined average flow of less than or equal to 1,000 GPD, or a structure with an average daily sewage flow of less than or equal to 1,000 GPD.

"Dilution area" means the land immediately adjacent to and down gradient, in the direction of ground water flow, from a mass sewage disposal system, which is provided for the purpose of diluting nitrogen, or other nutrients occurring in wastewater, with ambient ground water, in order to assure compliance with nutrient standards contained in this chapter.

"Mass sewage disposal system" aka “Mass Drainfield” - means a sewage disposal system or systems which will discharge effluent to a single absorption area or multiple absorption areas with or without combined flows, such that the loading rate applied to any acre, as determined by the department, exceeds 1,200 gallons per day.

"Treatment level 2 effluent" or "TL-2 effluent" means secondary effluent as defined in 12VAC5-610-120 that has been treated to produce BOD5 and TSS concentrations equal to or less than 30 mg/l each.

"Treatment level 3 effluent" or "TL-3 effluent" means effluent that has been treated to produce BOD5 and TSS concentrations equal to or less than 10 mg/l each.

References if you want to read more:
Definitions - https://law.lis.virginia.gov/admincode/title12/agency5/chapter610/section120/

https://law.lis.virginia.gov/admincode/title12/agency5/chapter613/section90/

Berkeley County South Carolina Sewer Connection

We are excited to share that AQWASTEP is now approved for use in Berkeley County, SC. We met with the director of the Berkeley County Sewer Department in early August 2019 and showed him our AQWASTEP system. His response to it was very favorable, and he agreed that it was a great alternative to on-lot grinder basins.

AQWASTEP allows property owners to connect to wastewater gravity or pressure mains without extending the main service line to their property.

This allows existing homeowners with failed septic systems or new development in outlying areas to affordably and efficiently connect to the local sewer on a lot by lot basis.

Berkeley County will approve our AQWASTEP tanks as an on-lot pump station for properties desiring to connect to sewer without direct access at the lot line.

If you want to learn more about AQWASTEP and would like to receive pdf and dwg cut sheets of the tank you would use, email us at info@aqwa.net or call 252-243-7693.

AQWASTEP System

AQWASTEP Flyer

Which Alternative Septic System is Best?

How do you make a decision about which alternative septic solution may be the best for you and your family?

Some of the metrics to assess when making a decision include:
Treatment Efficacy
Quality of Construction
Operations and Maintenance Costs
Ease of Maintenance
Aesthetics

We work with Advantex Treatment Systems because we believe they are best in class on all of those metrics.

Other treatment systems on the market don’t offer a treatment process that is nearly as robust and reliable as Advantex treatment systems nor are the materials used in their construction of comparable quality.

Aerobic treatment units (ATUs) have to be carefully managed in order to ensure that the treatment process does not push suspended solids into the drainfield. Normal Septic Tank Effluent will typically be less than 30mg/l total suspended solids (TSS). ATUs generate suspended solids as a part of their treatment process. These solids accumulate fairly rapidly and have to be pumped out every 1 to 3 years (generally) to avoid solids from entering the drain field. ATUs that are not carefully operated may effectively reduce the nutrient load found in the water but still produce effluent that has a TSS level north of 300mg/l TSS.

High TSS going to your drainfield will be the number one thing that causes it to fail prematurely by clogging the pore space in between the soil particles.

Advantex Systems reliably produces less than 10mg/l BOD, <10mg/l TSS, <20mg/l TN.

Advantex features stainless steel and fiberglass components designed to last the life of your home. These tanks and lids will withstand up to a 2,200 lb wheel load. The textile in Advantex units should never need to be replaced.

Pumps come with a 5 year warranty, all other components have at least a 3 year warranty.

Advantex are easy to maintain and do not require frequent pump outs of the tanks. The septic tank will need to be pumped on average every 5 to 10 years depending on use.

Have questions?

email us at info@aqwa.net or call 252-243-7693.

AXRT Brochure

AX20 Brochure

Above Ground Fiberglass Septic Tanks and Treatment Plants

Are you looking for an above ground septic tank option? We use Orenco T-MAX units on many of our commercial jobs when burying a concrete or fiberglass primary tank will be difficult or costly due to high water table, shallow bedrock, or other site conditions.

The T-MAX tank can come in a variety of configurations that allow for flexibility and customization based on your application. You can gravity or pump out of these T-MAX units to the next treatment stage. Typically we are going into an Advantex AX-MAX treatment unit but really they could go anywhere.

We currently have a project installation in process at a campground in the mountains of Virginia. Due to the difficult site conditions, shallow bedrock, unstable soils, and difficult access for an excavator, the project engineer with AQWA guidance elected to use a T-MAX unit for the flow equalization tank followed by an AX-MAX Mobile set at grade.

Using the T-MAX and AX-MAX Mobile allowed for easy and quick installation of the system with minimal digging required. Check out the Technical submittals for the T-MAX and Mobile units.

Interested in learning more or have a project in mind? Reach out to us to learn more and get started by emailing info@aqwa.net or calling 252-243-7693.

60,000 gpd treatment system featuring T-MAX primary tanks and AX-Mobile treatment units.

NPDES Permit - How to reduce O&M costs of your package plant

If you are considering replacing an activated sludge plant in South Carolina, North Carolina or Virginia now is a great time to ask yourself, “Is there a better way to do this?”

Activated sludge plants treating small flows <100,000 gpd are tricky to operate. They require lots of maintenance, use lots of energy, and are prone to treatment process upsets due to variable flows and flow strengths.

NPDES permits almost always require a minimum of 5 visits per week (daily) by the operator in charge. This number of visits is required because you actually have to go to an activated sludge plant that often to make sure it is running properly.

There is another option out there that approaches small flow wastewater treatment differently using a packed bed media filter instead of activated sludge process.

This packed bed media filter process is a much more robust treatment process that is less prone to upset utilizing a non-submerged media filter on which the nutrient digesting bacteria live and thrive. In low-flow and low-food times, the bacteria consume what nutrients are left in the recirculating wastewater before entering endogenous respiration aka cannibalizing themselves and each other to survive until flow and food returns. (You can read more about the Performance of Packed Bed Media Filters here.)

The Advantex technology, especially the AX MAX is a technological break through bringing the benefits of packed bed media filters like sand filters to a larger scale economically. Advantex treatment systems have been used to replace existing activated sludge package plants resulting in:

• 80% reduction in site visits

• 90% reduction in sludge pumping

• No more energy hogging blowers

• More consistent treatment and effluent quality

• Expanded flow capacity

• Fully Telemetry enabled

• Safer work environment

Do you have an activated sludge package plant in North Carolina, South Carolina, or Virginia?

If you do, reach out to AQWA to find out how an Advantex system can replace your existing package plant resulting in huge recurring annual savings on operations and maintenance.

call 252-243-7693 and ask for Michael or Steve

or

email info@aqwa.net

Don't Lose Money, Unlock Highest and Best Use with AQWA

When appraising a property, the question of "What is the highest and best use of a property?"  is asked by appraisers or potential buyers in order to arrive at an accurate estimation of market value if the property were to be sold.

This process of determining highest and best use is both an analytical and a creative process requiring the appraiser to not only see the property for what it is, but what it can become while also being:

• Legally permissible

• Physically possible

• Financially feasible

• Maximally productive

To effectively answer these questions, one has to be well-versed in local law, zoning, permitting, limiting site conditions, property values, market trends and consumer or investor demand.

For properties without access to public sewer, the onsite wastewater or septic design will oftentimes be the single most limiting factors for how a property can be used.

We help you overcome these constraints by thoroughly understanding how onsite wastewater collections, treatment and dispersal can reduce the legal, physical, and financial barriers that stand in the way of maximally productive property. 

Very few people see the most creative and efficient way to treat and disperse wastewater long-term at first glance.  Having been in the business for 15+ years, we have seen dozens of techniques that change the value of a property or development by 6 or even 7 figures with one critical decision concerning wastewater. 

AQWA also operates and maintains over 500 wastewater treatment systems in the Carolinas which gives us a unique perspective of how initial design considerations impact ongoing operation and maintenance cost.

When buying a property, selling a property, or developing a property, knowing what your options for development are is key to meeting your goals AND  not leaving huge amounts of money on the table.  Read more about how we do that for commercial systems, residential systems, and STEP Collections that bring sewer to you.

Call us at (888) 552-AQWA  or   Email   info@aqwa.net to get the conversation started.

AQWA Expands Territory to Virginia

AQWA Inc., (Wilson, NC), the AdvanTex® dealer in the Carolinas, is pleased to announce the addition of Virginia into its market territory.

Orenco Systems (Sutherlin, OR), the manufacturer of AdvanTex Wastewater Treatment Systems, has authorized AQWA Inc. to bring its unmatched sales and service team to engineers, developers, commercial facility owners, utilities, and municipalities throughout the Commonwealth.

The AdvanTex line has grown in recent years to include a larger, modular AX-Max™ system, which allows for phased installation for flows from 5,000 GPD up to 100,000 GPD or more. Clean effluent from these units is safely discharged to the environment through drip or spray irrigation, traditional drainfields, or direct NPDES discharge. “The AdvanTex Treatment System is the closest thing to a bullet-proof wastewater treatment system out there. Now, it’s our job to show everyone what it can do,” says Steve Barry, AQWA’s President.

He continues: “With the focus on nutrient limitations in the Chesapeake Bay and Smith Mountain Lake regions, growth pressures in Northern Virginia, as well as environmentally sensitive trout streams in the Blue Ridge, we expect the AX-Max to be very well received in Virginia.”

Since Orenco introduced this product for larger flows, AQWA has made significant inroads in the Carolinas, including groundbreaking systems installed in several new decentralized subdivisions on Lake Norman NC, in a nuclear power plant, and in state parks, RV parks, and several schools.

“Our new mission is to rid the world of traditional aeration ‘package plants’. They are simply the wrong technology for flows less than 100,000 gallons per day,” according to Barry. “If we don’t get rid of those tired old ‘package plants’ and replace them more stable and scalable technologies like the AX-Max, the environment will continue to suffer and owners will continue to pay too much. We’re going to keep doing everything we can to leave cleaner lakes and rivers to our kids and grandkids, and this is another step along that path.”

Since 2002, AQWA, a family-owned business, has relentlessly worked to be The Clear Leader™ in wastewater treatment equipment sales and service in the Carolinas. “We’ve been blessed in so many ways. We have a great partner in Orenco, as well as diligent employees with high integrity. Their hard work has earned the respect of regulators, engineers, installers, soil scientists, and property owners alike.” Barry says.

How to get more bedrooms out of your septic permit

There are 2 major ways to get more bedrooms approved for your septic permit.

1) Increase your LTAR (long-term acceptance rate). This number describes how many gallons per day per sq ft of drain field space can be applied sustainably to the soil without failing. 

2) Reduce your horizontal setbacks and open up more area on the property for drainfield area. Treating wastewater before applying it to the drainfield area allows property owners to reduce the horizontal setback distance they must maintain between their drainfield and property features like: foundation drains, surface waters, and interceptor drains. 

If your property is near a body of water like Lake Norman or on the coast we oftentimes utilize a combination of both 1 and 2 through the use of treatment technology, innovative drainfield products and a thorough understanding of onsite wastewater rules.

For example, on Lake Norman, where soils are normally pretty good, a drainfield product like T&J Panel is used to reduce the required footprint of the drainfield by 50%.  By pairing T&J Panel’s 50% drainfield reduction with the horizontal setback reductions of Ts-i or ts-ii treatment, homeowners are able to gain additional bedrooms, pool area, or other valuable additions to their property.

At the coast, we use ts-ii treatment and bed systems to squeeze drain fields for an 8 bedroom home in to a little over 400 sq ft.

The 1970 Rules are the rule book in North Carolina that the local environmental health department and soils and engineering professionals use as guidelines for septic system design.

Thankfully the 1970 rules are undergoing a rewrite to make them more readable and easily understood. In the meantime, reach out to AQWA for help tackling your onsite wastewater design challenges! info@aqwa.net