use of Treated sewage effluent for construction

[JECCNC]

I have a situation where contractor is asking to use TSE water for compacting back fill material, the back fill is mainly sandy soil and is below a steel pipe rack. can any one help with the advantages and disadvantages of this action? are there any adverse effects of using TSE on soil

 

[Ron]

Corrosion potential is higher, it will likely add sulphates to the soil which can affect concrete, and you might not be allowed to do so because of local or regional environmental laws (similar to effluent spray field application)

 

[bimr]

Sewage effluent is not going to be significantly more corrosive or have any more sulfates than the water supply that the water was initially sourced from

The only concern that you should have is for contact with the workers. The effluent water should be disinfected as a minimum requirement. You may have to filter the effluent in order to get proper disinfection.

If the effluent is not thoroughly treated, you may have some temporary odors.

 

[stanier]

It depends on the treatment process for the effluent. If it is only screened and chlorinated expect very high corrosion levels. if it has been membrane treated then BIMR could be correct.

 

[shirsch]

The WWTP where they get this treated effluent must have a land application NPDES permit to discharge onto soil and this permit has a specific site where the effluent must be discharged. I have never heard of a contractor wanting to use treated effluent for compaction and I have never heard of an NPDES permit that would allow the WWTP to provide a contractor with treated effluent to be used for compaction. Doesn't sound right to me.

 

[ptmoss]

Depending on the state, individual septage pumpers/haulers can get permits to dispose of the septage on fields after screening and treatment, usually adding lime.

Could be the contractor was going to make a few bucks by being able to dispose of it for a hauler.

It would definitely need a permit. I hope JECCNC said no unless there was a proper permit in place and the concerns above regarding corrosion, etc. were considered.