GSMarshall
Civil/Environmental
- Feb 28, 2024
- 1
I am working on a group of temporary office/training buildings. 8 buildings totaling just under 19,000sf. We have calculated an occupant load of 491 people ~ rounding to 500. Based on some research I'm calculating about 13 gal/person/day ~ 6500gpd.
Due to site constraints, I can't tie into gravity sewer directly so I'm looking at a small pumping solution. obviously I don't need a 6500 gal tank/station but I am troubled with converting the gpd to gpm to size my pumps and tank. I suppose much of the flow will be used during the lunch hour and I would not want a situation where the flows backup into the trailers.
I've been looking at some prepackaged pumping solutions like Little Giant.
This project is in northern Florida for a US govt owned property so permitting and engineering requirements are atypical.
We don't have a detailed topo survey but based on a site visit, I believe we are looking at about 15'-20' max head depending on pump elevation inside the tank.
my quesitions:
1) is there a good resource to backup flowrate calculations?
2) Best way to convert GPD to gpm for pump sizing?
3) Am I underestimating the station design and should be looking at a much larger, standard, lift station?
Please keep in mind that this is not expected for a 30 year duration as it is temporary trailers, however you know how "temporary" ends up being more long term than originally planned. (see schools and churches for example)
I will state that the gov't does allow for contracting a pump-and-haul solution but I don't think they want to be forking over $ daily/hourly pump-and-haul.
FYI, this isn't my first foray into lift station design, it's just been a few (15) years.
Due to site constraints, I can't tie into gravity sewer directly so I'm looking at a small pumping solution. obviously I don't need a 6500 gal tank/station but I am troubled with converting the gpd to gpm to size my pumps and tank. I suppose much of the flow will be used during the lunch hour and I would not want a situation where the flows backup into the trailers.
I've been looking at some prepackaged pumping solutions like Little Giant.
This project is in northern Florida for a US govt owned property so permitting and engineering requirements are atypical.
We don't have a detailed topo survey but based on a site visit, I believe we are looking at about 15'-20' max head depending on pump elevation inside the tank.
my quesitions:
1) is there a good resource to backup flowrate calculations?
2) Best way to convert GPD to gpm for pump sizing?
3) Am I underestimating the station design and should be looking at a much larger, standard, lift station?
Please keep in mind that this is not expected for a 30 year duration as it is temporary trailers, however you know how "temporary" ends up being more long term than originally planned. (see schools and churches for example)
I will state that the gov't does allow for contracting a pump-and-haul solution but I don't think they want to be forking over $ daily/hourly pump-and-haul.
FYI, this isn't my first foray into lift station design, it's just been a few (15) years.