Question about private sewer billing

[Tony H.]

I'm looking at a mobile home park that has city water and a sewage lagoon. The park is currently paying for water, so it looks like it could save several thousand a year by submetering, though I had a question about billing tenants when they are on private sewer. From the park's P&L, the cost for maintenance of the lagoon is around $2400 / year, plus electricity to the pumps, etc. (includes testing, chemicals). Is it possible (or legal) to bill that cost back to the tenants, and if so, how would I go about doing that? Would it just be (cost / lots) / 12? Thanks for the help!