The Brew Cabin

Posted: **Sun Jun 03, 2012 7:53 am**

Hi Guys,

Need a bit of advice....

On sandy soil and having had a big soakaway added to the system using the crates I have had no issues with my system for around 5 years...However, after recent heavy rain falls the system has started to back up again

We are a family of four with two young children so the system sees a lot of action with bath water, washing machine, dishwasher etc all contributing...

I can see two option:

1. Add a further drainage field to the tank at the bottom of the garden, set at a higher level as a support system for the main soakaway...

2. Divert grey water into a new drainage field or soakaway in the top section of the garden

TBH I favour the later option as this will help keep this section of the garden watered which can get dry in the summer and it will make a significant impact on the volume of water going into the main tank....

I am aware that technically all the water should be processed through the main tank, but with water harvesting more relevant these days am willing to take this chance.

So basically I'm interested in your thoughts on my options, also recommendations for the grey water half of the system....At most it will be taking the washing machine, and dishwasher plus one hand basin, but I want to over engineer this to avoid a future repetition of the work....

Posted: **Sun Jun 03, 2012 9:14 am**

If the flooding is related to rainfall you need to check that you dont have any storm water entering the tank inlet, if you do divert it to its own soak-away.

It is more likely that the crates you installed are draining the lawn and the water is surcharging back through the tank.

Simple fix is to install a pump chamber on the outlet of the tank, this will lift the waste water into the soak-away but stops water returning to the tank

Posted: **Sun Jun 03, 2012 9:30 am**

flowjoe wrote:If the flooding is related to rainfall you need to check that you dont have any storm water entering the tank inlet, if you do divert it to its own soak-away.

It is more likely that the crates you installed are draining the lawn and the water is surcharging back through the tank.

Simple fix is to install a pump chamber on the outlet of the tank, this will lift the waste water into the soak-away but stops water returning to the tank

Ok, sorry to be dense but I'll need a little more help with this....the tankout let is ceramic and goes into an old clinker type chamber, the crate system runs off of that. The clinker chamber is filling up...so I agree this could well cause back flow, but at the end of the day I need to get the water moving around the garden to spread the load....

Maybe some pics would help....

Posted: **Sun Jun 03, 2012 9:43 am**

If the clinker bed is clogged up and you get flooding after rainfall you have two problems, firstly you have rainwater running through the tank and secondly the filter media needs excavating and cleaning.

If the water is coming back from your crates, through the filter tank and into the main tank then the crates are not coping and water being water it is taking the path of least resistance back to the tank, by installing a pump you are sending the water to the crates and it can not return.

So unless you have a known issue with the crates (such as waste water lay at surface level) the water will disperse into the sub-soil because it can not get back to the tank.

I have never used crates for a tank soak-away, if you have wrapped them in a geo-textile grease, fat and fibres will eventually seal it all up nicely so make sure the filter chamber is maintained !

Posted: **Sun Jun 03, 2012 10:19 am**

flowjoe wrote:If the clinker bed is clogged up and you get flooding after rainfall you have two problems, firstly you have rainwater running through the tank and secondly the filter media needs excavating and cleaning.

If the water is coming back from your crates, through the filter tank and into the main tank then the crates are not coping and water being water it is taking the path of least resistance back to the tank, by installing a pump you are sending the water to the crates and it can not return.

So unless you have a known issue with the crates (such as waste water lay at surface level) the water will disperse into the sub-soil because it can not get back to the tank.

I have never used crates for a tank soak-away, if you have wrapped them in a geo-textile grease, fat and fibres will eventually seal it all up nicely so make sure the filter chamber is maintained !

Don't suppose you are Kent based by any chance

Posted: **Sun Jun 03, 2012 7:35 pm**

Sadly not Simon, i find the southern rain to be too warm and not frequent enough.

I have sent you a PM with a number for a contractor in Folkestone

Edited By flowjoe on 1338748583

The Brew Cabin

Septic tank soakaway problem