I think everything we have all said is correct, it just comes down to the math as Greg said. Use a cap rate drop of 1.5, plus the cost savings, plus the pass through if you can. Just do the math, figure out the payback time and make a decision.
I did some rough math like this, anyone feel free to scrutinize my math. I do not represent my math to be exact, just an example.
Value on lagoon, 35% expense ratio 80X215X12X.65/.1 for a 10 cap = value of 1.34 mil
Value on sewer, 30% expense ratio 80X215X12X.7/.085 for a 8.5 cap = value of 1.7 mil
That plus passing through the expenses on the capital improvement may make it very interesting, not to mention it likely would sell a lot quicker. Again, NOT saying my figures are the correct ones, just giving an example, re-figure using the correct numbers and let us know please.