Septic Tank

peterc14

Nearing the stage to put external drainage pipes in. The Architect says we have been approved to use a "standard" Septic Tank...

1) Is there differences in the types of Septic Tank?
2) What are the advantages of one over another?
3) Is there anything worthwhile doing at this stage in relation to Septic Tank size/position/type etc to save bother further down the line ie with cleaning/emptying it etc

Bullseye1

Check with your Architect and the Planning Authority if your permission allows for an upgrade from a standard septic tank to a mechanical version (run on electricity and serviced once/twice a year). If your on a well for your water it offers better effluent and protects your water source. Whatever you chose it should have an up to date Irish Agreement Certificate.

It may however require a further planning application that is why I recommend consulting your Architect.

PaleRider

1. A large rectangular tank is a good option.
2. Concrete is good. Go for larger tank.
3. Locate tank close to kerb line so as to allow easy access for emptying.
4. Access to hose is good for cleaning/servicing.
5. Fence of percolation area
6. Don't dispose of kitchen waste in tank/grease/oil etc
7. Plan a reserve percolation area/ if soil poor.
8. Follow EPA 2009 guidelines. Check epa.ie wastewater treatment for single houses
9. Photograph installation
10. Carry out work in good weather.

Standard tank fine if used carefully. Your soil must be good to get approval for standard tank. IAB approved important.

Supertech

Check with your Architect and the Planning Authority if your permission allows for an upgrade from a standard septic tank to a mechanical version (run on electricity and serviced once/twice a year).

I wouldn't necessarily agree Bullseye

If the site has been assessed using the EPA Code of Practice, and been found suitable for use of a septic tank, then there shouldn't be any need to upgrade to a proprietary system - such an upgrade will likely see an increase in costs for the OP, aswell as unneccessary running costs, and servicing.

As you rightly say, it will almost certainly involve a new planning application in any case.

Most of Pale Rider's observations above are correct, but the most important one is No.8 - stick to the EPA guidelines.

There's a lot of issues around septic tanks at the moment, and there's likely to be significant changes in legislation not too far down the line and at the moment the EPA CoP's are the benchmark for what needs to be done on site.

gman2k

PaleRider wrote: »

1. Don't dispose of kitchen waste in tank/grease/oil etc

Install a grease trap. All waste should go to the septic tank.
I have my pipe runs separated so washing machine, kitchen, showers, whbs go to grease trap first before entering the main foul line which carries toilet waste.

Bullseye1

Theres no doubt it may need a new application but that would depend on the wording employed in the application. If they used Waste Water Treatment unit instead of septic tank they have allowed for a multiple of choice. I agree it will add to the cost but in this day in age standard septic tanks are stone age technology. Personally I'd go for something alittle more up to date. But obviously budgets will ultimately determine the OPs decision.

Supertech wrote: »

I wouldn't necessarily agree Bullseye

If the site has been assessed using the EPA Code of Practice, and been found suitable for use of a septic tank, then there shouldn't be any need to upgrade to a proprietary system - such an upgrade will likely see an increase in costs for the OP, aswell as unneccessary running costs, and servicing.

As you rightly say, it will almost certainly involve a new planning application in any case.

Most of Pale Rider's observations above are correct, but the most important one is No.8 - stick to the EPA guidelines.

There's a lot of issues around septic tanks at the moment, and there's likely to be significant changes in legislation not too far down the line and at the moment the EPA CoP's are the benchmark for what needs to be done on site.

Bullseye1

Oh with regards to servicing of septic tanks they too should be desludged on an annual basis. I don't think electrical costs on running the system is significant but maybe someone can chime in on the approximate cost per year to power one of these.

gman2k

Bullseye1 wrote: »

...but in this day in age standard septic tanks are stone age technology. Personally I'd go for something alittle more up to date. But obviously budgets will ultimately determine the OPs decision.

Stone age technology in this instance works perfect, if the ground conditions allow it.
In the OP's case, a site suitability report would have been carried out, which would have proved to the planners that the site is suitable for a septic tank.

There is no need to provide any sort of additional treatment plant, as the septic tank and percolation area - if designed, installed & maintained correctly - will treat all waste properly without any risk to the environment.

My only other advice to the OP is to install a precast concrete tank as opposed to a plastic, only a few hundred euro extra, but will last forever.

peterc14

Thanks very much for everyone taking the time to reply... interesting to hear people's thoughts.

peterc14

gman2k wrote: »

Install a grease trap. All waste should go to the septic tank.
I have my pipe runs separated so washing machine, kitchen, showers, whbs go to grease trap first before entering the main foul line which carries toilet waste.

Can you explain a bit more about the grease trap and how this would be installed into the drainage layout? I assume it needs cleaned out fairly often? What size do they come in?

sydthebeat

peterc14 wrote: »

Can you explain a bit more about the grease trap and how this would be installed into the drainage layout? I assume it needs cleaned out fairly often? What size do they come in?

they usually are prefabricated and can come in sizes of about 50 litres. The basiclaly stop the run of the liquid and allow and suspended solids to coagulate in an area where they can be removed.

see here for an example.

There are many product on the market and i am in no way touting this particular one. I have no direct experience with this company.

peterc14

Concrete or Plastic?

What would people recommend and why?

sydthebeat

peterc14 wrote: »

Concrete or Plastic?

What would people recommend and why?

are you talking about effluent treatment systems?

gman2k

peterc14 wrote: »

Concrete or Plastic?

What would people recommend and why?

A concrete septic tank is a much more substantial piece of kit.
It is not prone to cracking during the lifetime of the owner, unlike a plastic one, which are often cracked by heavy machinery/ tractors driving very near to them.
There are many sellers out there for conc tanks, just pick the one local to you!
They will also supply the conc risers, lids and distribution boxes.

peterc14

sydthebeat wrote: »

are you talking about effluent treatment systems?

just the bog standard septic tank.

sydthebeat

peterc14 wrote: »

just the bog standard septic tank.

concrete all the way.

plastic tanks depend on EPDM gaskets etc and i dont see them lasting 60+ years. The risk of buckling is also higher in a plastic tank.

Concrete 2 chamber tanks are the best option in my opinion.

peterc14

Thanks for all the replies. I have researched a bit more and think that concrete is the way to go.

What shape would people recommend... does the shape matter? Are they all two chambers?

Someone tols me that the "Figure 8" type may not be good because of the join in the concrete... would the rectangular be the way to go?

sydthebeat

peterc14 wrote: »

Thanks for all the replies. I have researched a bit more and think that concrete is the way to go.

What shape would people recommend... does the shape matter? Are they all two chambers?

Someone tols me that the "Figure 8" type may not be good because of the join in the concrete... would the rectangular be the way to go?

you need two chambers. Single chamber doesnt comply with regulations such as SR 6 1991.

personally havent heard of any issue with the "figure 8" type.

exaisle

sydthebeat wrote: »

you need two chambers. Single chamber doesnt comply with regulations such as SR 6 1991.

Am I mistaken in thinking that SR6 1991 has been superceeded by EPA Guidelines 2009 and indeed 2010....?

Supertech

No you're correct. EPA Manual and Part H of Building Regulations 2010 are the current regs.