But then there are these paragons of engineering that we plan reviewers are faced with:
I just went out on an inspection, because the project "engineer" insisted he wasn't building on top of an existing septic system, despite the fact that a site topo he submitted seemed to say he was.
So I get out there, and the guy is building on top of a large septic system, belonging to the adjacent building (which raises all sorts of interesting questions about land ownership and such).
Pretty much no need to nitpick on that application, but I will anyway - they deserve it.
I've been on both sides, done peer review and compliance review for large FDA regulated process control systems...
there are idiots on both sides...
I put a small pump station in...30 EDU's
I used 265 GPD/EDU (water records put it at 165GPD/EDU actually)
I used a peaking factor of 2.5 (DEP guideline), and a duty factor of 25%, growth factor of 20%...I threw 20% on top for infiltration, it was a new system, no stormwater inflow...houses were close, not a lot of pipe...no chance of growth...that's why it took 20 years to sewer...
30 x 265 x 2.5 x 1/0.25 x 1.2 x 1.2/1440 ~ 80 GPM, he told me to size it at 200 GPM (no idea how he came up with it, think he used 400 GPD/EDU, which is for sizing the pipe)...
I told him I thought 80 was too much, and that 40 would do...
the pump runs ~25 min per day! septic sewage...the floats are 1' apart the pump runs ~1 minute (5' wet well), then sits for almost an hour...
the forcemain was sized for the pump, so it has too much volume exasperating the problem...
we got an oder complaint...he showed up...I explained the problem, and showed him his 'directive'...but guess what? it's still our problem, not his...
so we have an oversized electrical system, forcemain, genset, etc.