Plumbing vents routed through the roof are an unlikely source of the odors. If they were, all residential suburbs (sewered or unsewered) would stink like heck.
A more likely source of the odors are failing septic tanks and leach fields in the area. This is particularly common in communities...
Methanol can be a good food source to get things goingj, depending on local availability. Another approach is to import WAS from a nearby WWTP. Add the WAS or methanol about a month before the flows arrive to give the process time to acclimate and build up biomass in the aearation basin...
Over the years I've found that the best way to specify any type of soil is to use the standards developed by the transportation department for the state the project is located in. Sometimes the county where the project is to be constructed will have local standards - in that case it is best to...
I agree with your decision to restrain all of the joints. With only 2-ft of cover the soil will not have much passive strength to support a thrust block.
Don't bother with calculating the required restrained length because with uncompacted backfill there won't be enough skin-friction to...