Septic Permits and Building Permits

The Advantage of Simultaneous Building Permit and Septic Permit Applications

           

Over the years, country residential lots have gotten smaller. This has not restricted the size of the homes being built on them. Some of these homes have very extensive floor plans.

When we get the call to do a septic design for one of these larger homes, too often we find that the house has already been started and our hands are tied.

Once we layout all the required setbacks, we find ourselves a little short of the area needed for a treatment system that will meet the requirements of the Private Sewage System Standard of Practice (SoP).

To make matters worse, the desire to save farmland results in land that is not farmable being selected for subdivision into residential lots. Unfortunately, often land that is not suitable for agriculture is not suited for septic treatment either.

How often have we, as designers, been told - “Oh, I thought we would put the septic field down in that lower area? It should drain naturally. We won’t even need a pump?”

And of course, the house sits in the one high spot that could have properly treated effluent without too many limiting factors.

Or how often have you struggled to shoehorn a field into a very tight side-yard, knowing that if the house had been placed 30 feet to the left, a field would have fit in easily?

           

The problem is not necessarily the small lot or the big house. If we have good soils
and a small house, a lot as small as ¼ acre will meet the requirements of the Private Sewage System Standard of Practice (SoP), with room to spare. A two-acre lot will meet the needs of a four to six bedroom house. This assumes of course, that the placement of house, the well and the septic system on the lot are all thoughtfully considered.

And therein lies the main problem! Most of the time, Builders are focused on the house and look at the septic treatment system as an after thought. They are not aware that the septic treatment system cannot be on disturbed soils and that it needs at least five feet of good soil under it that is not saturated. They are shocked to find out that their lack of septic knowledge may cost them tens of thousands of dollars. What might have been a simple system now has to be a raised mound or require additional treatment to meet the intent of the SoP.

 

Raised treatment mounds are a very good solution for problem areas but are a bit more money than the standard tile and stone.

How do we solve this problem?  Really, it’s quite simple. If the authority having jurisdiction (A.H.J.) only accepts building permit applications that are accompanied by a completed septic system design, the problem will be solved. It is important that both applications be the final version, “approved for construction.” We need the actual septic design. Not just a rectangle drawn on the site plan with the notation “septic system here.”

And this is the responsibility of the A.H.J. They allowed the subdivision and by accepting the building permit application, they are allowing the size and location of the house. So at the end of the day, the A.H.J. has to allow the septic system even if it doesn’t meet the prescriptive requirements of the SoP!

The site plan for both the building permit and the septic permit applications should be the same. This should ensure that the house and well are placed in such a way to allow for a SoP approved septic treatment system. Setbacks from neighbouring facilities should also be noted.

On these higher density residential developments, we definitely need to take into consideration what is happening on the neighbouring lots.

            Does the place left for the soils based septic treatment facility have the required setback from the neighbour’s well?

            Will that field or mound on the other side of the property line cause our system grief?

Consider that if each field is only five feet from the property line, we can be quite sure that if there are any near-surface restrictive layers, both systems will be subject to ground water mounding and eventual failure.

Some jurisdictions now require subdivision applicants to provide proof that a parcel can be serviced by a soils-based treatment facility meeting the requirements of the SoP. A full site evaluation is required prior to allowing the subdivision of that parcel from the parent parcel. This is a good first step.

 If those of us doing the original site evaluation note any size restrictions due to the land and soils inventories, we must record this in a fashion that allows the A.H.J. to take steps to prevent future problems.

As site evaluators, we need to do our due diligence as per section seven of the SoP. If we follow section seven and build our report as prescribed, we need to highlight any wet areas and any other restrictive surface or subsurface considerations that will impact the ability of the parcel to treat effluent. It is important that we identify which land areas are suitable for treatment and which are not. The smaller the lot, the more important this is. It is so disappointing, when we are investigating a failure, to find that the original documents submitted to the county are just a precast supplier’s fill-in-the-numbers form. When we see this, we know why the system has failed! Section seven of the SoP needs to be followed! And that includes a full written report!

However, the septic site evaluator often has no idea what size of house will eventually be built on the new parcel.

If the home designer has full knowledge of the septic designer’s requirements, it is relatively easy to make sure the design of the house compliments the rest of the site’s requirements.

Sometimes, the solution might be as easy as shifting the house location a bit or possibly to build a two-storey home rather then a bungalow, thereby freeing up more area for the soils-based treatment facility.

Building a house on the lower wetter area is often simpler than to design a treatment area on these restrictive soils. The area for the house can be built-up with imported soils where-as the septic system must be installed on undisturbed soils.

Making these adjustments to the design or location of the house are simple solutions if done prior to putting a shovel in the ground but impossible to do after the house has started.

The requirement for simultaneous applications of permits should not be restricted to new homes. It is just as important for renovations or additions.

If you are going to add bedrooms to a home, you will need to increase the size of both the tank and the soils-based treatment facility.

Additionally, this is a good time for the A.H.J. to catch failed systems or systems that no longer meet the requirement of the SoP. A new home should never be attached to an existing system without full evaluation of the old system.

It would be irresponsible to allow an even greater demand to be placed on an already failed system or one that will fail in the near future.

In all cases of small lot size and high-density residential developments, the A.H.J. should insist that the soils-based treatment facilities, be preceded by an advanced treatment unit.

Norweco's Singulair Green Advanced Treatment Unit

We know that the SoP allows for primary treatment as low as 150 mg/l of cBOD₅, 100 mg/l of TSS and 15 mg/l of grease.  That leaves a lot of suspended solids in the effluent that will hide pathogens and clog soil pores.

The better advanced treatment units will produce results that are 90 percent better than the SoP’s base requirements. As an example, Norweco’s Singulair Green produces average results of 4 mg/l cBOD₅, 9 mg/l of TSS. In practical terms, this means the effluent is so clear, it looks like normal tap water. Along with the removal of the suspended solids, a high percentage of the pathogens are destroyed.

This highlights one of the advantages of advanced treatment units. If there is a failure of the soils-base treatment facility, any effluent surfacing or running onto a neighbour’s property, will be at about 90 percent treated. Consequently, the surfacing effluent will not have the offensive odour or pathogen load of effluent that has only been treated by a standard two-compartment septic tank. This prevents most of the health concerns and possibly avoids a neighbourhood feud. Neighbourhood feuds always have a way of winding up at the county office, so requiring advanced treatment will save the county a bit of grief.

The use of advanced treatment units usually reduces the incidence of system failure anyway. We know that a major cause of failure is a build-up of bio-mat that blocks the soil pores. This is due to effluent with high TSS (total suspended solids) content being dosed to the field. We also know that a top of the line advanced treatment unit like the Singulair Green removes up to 90 percent of the TSS. We can therefore be assured that advanced treatment will reduce the probability of failure by up to 90 percent.

This is very important in small lots. Nobody wants to tear up the landscape just as it finally starts to mature!

And of course, if you are going to use an advanced treatment unit, select one that has both a place for the good bacteria to colonize as well as sufficient filtration. These two additions to the treatment methodology will supplement the aeration process to product clear effluent in almost all temperature conditions.

Please don’t select those that just rely on pumping in hundreds of liters of air. Pumping freezing air into the treatment tank will certainly cause the good bacteria to go into dormancy or die off during that weeklong cold snap in January. And pumping warm moist air from a basement through frozen ground will almost always produce condensate that will plug the air line either by filling a dip in the line or by actually freezing. Look for a self-contained advanced treatment unit that uses internal air in the minimal amount needed to achieve the required reduction of TSS and cBOB₅.

The author Bob Boersema is a senior private sewage system designer, specializing in small lots and difficult soils inventories. He lives in the south central part of Alberta.

            “Every home deserves a treatment system that meets the intent of the SoP.”

Bob is also a building designer and contractor with a perchance for energy efficiency. Not only does he understand the SoP but has a good working knowledge of all building codes.

            Bob may be contacted at aftertheflush@hotmail.com or www. aftertheflush.ca