I have an excellent and reputable contractor in Stamford. I can set up a FREE quote for you, as the cost will vary and depend on the size, accessibility, etc. :)

You need to be extremely careful if you want to fill in a pool, suggest speaking to all contractors for opinions and etc. there is plumbing issues, sink hole and much more.

Many homes are valued higher with pool now in residential market families have limited budgets for travel seeking backyard as an escape with entertainment

It depends on a lot of factors. The size of the pool, width & depth. If the pool is concrete or gunite and / or has concrete surrounding the pool, then then can be used to fill in the pool. Usually fill dirt and / or stone will needed to be bought and brought on-site. The more rock the better, just fill dirt will settle over time.

There also may be some zoning laws that are of concern. Check with your local zoning board.

Consult with a general contractor in your area to get a better idea.