For the lot to be approved for development, it's likely the approving authority will require a successful perculation test be performed and certified for your septic system.

Drilling wells for domestic water is a matter of how deep one may have to go (and how much money it will take). If you talk to a couple of experienced drillers in your area, they will probably share with your their general experience for drilling and finding water in your area.

You will want to have the water tested for safety and impurities, so that it is safe, potable water and you know if you will need treatment for hardness, taste, etc.

Drilling should be feasible close to your house location in order to reduce expenses. Until you site your house, you really can't select either the well or septic location. There are regulations about the minimum distance that the two may be for one another.

Another issue for wells is house water pressure. You may need a pressure tank and booster pump in order to achieve consistent and desirable water pressure throughout your house. If you desire outdoor sprinkler irrigation, that should also be considered.

Finally, the equipment that may be needed for a well--pressure tank, softner tank, hot water heater, etc--will likely mean an available space large enough for all of these, plus the space to work around them for maintenance and repair. These will not fit into a standard coat closet!

Good luck with your project.

Well water is more likely to need a water treatments system for impurities. Those impurities can be mineral, or chemical or biological. Your local Health Department will generally have information about the general quality of the local water.

You also will be dependent on an electric pump for your water system to operate. A big storm knocks out your power for a week, that also means that you are out of water for the week, not just the other electrical conveniences. If you have natural gas to the property, or propane, you should investigate designing the home with a sub panel for essential needs and powering that panel with a generator. If you do that from the beginning, it's much easier than attempting to retrofit at a later time.

Well water and septics also mean restrictions on how you landscape your property. You need to site the home and these systems before developing a master landscape plan. You cannot have any hard scaping or deep rooted plant matter near either one of the systems. Generally, grass or shallow rooted plant matter like a herbaceous plant bed are OK, but deeper rooted things like trees and large shrubs are not. Bear in mind that if you locate a desirable feature on top of a septic field or next to the well head, it has the potential for being dug up if there are issues down the road.

Well water to some people means "free" water. But that isn't the case. You pay for the electricity to pump that water, and you and your neighbors pay if the aquifer from which you've tapped that water has excessive demands on it. So, wise water use planning for the home from the beginning should be considered. If you want one of those massive jetted showers, you'll incur a lot of expense to make it happen, and you'll be wasting a lot of potentially valuable drinking water down the drain. If you live in a dry climate, look into xeriscaping for your landscape in order to reduce your water needs. And if you do want that many sprayed shower as an occasional indulgence, make sure that you have enough pressure tank and hot water tank to handle it, and that the accessory units are pipes and valved separately from the every day 5 minute am shower head.

In addition to what the others have said, well water can have "character". It may have a metallic taste or smell that not everyone will enjoy, even if it's perfectly healthy to drink. I grew up with well water, and if we went on vacation, the water would sometimes be red when we returned-- we'd let it run a couple minutes and it would be fine again. Something about the iron-rich water sitting made it happen. It was a little alarming the first time it happened, but it was harmless and temporary.

You may find yourself buying bottled water or filtering your water for drinking, unless you're like me and can drink almost anything wet, as long as it's good and cold. :)

My advise - hire a dowser to help decide where to drill for a well. We only did this after the first "well" came up dry. We should have done it before any drilling was done.

Most, if not all counties I'm familiar with publicly record information on well depths and how much water the well produces. So you can check out the records for the wells near you and see how deep they tend to be, for example, as well as how productive they are. In our county, you have to show you can get 400 gallons per day to get a building permit for a house. Some people have wells that just trickle, and have to store it for domestic use. Water quality is so variable from one place to another and even locally, that it is hard to say anything meaningful about a well at your location. Our well water is reducing and has a sulfur-y smell until it sits for a while, so we had to install a filter and softener in addition to a pressure system. Get a water quality analysis for at least the major ions and find someone who knows what those numbers mean to advise you. (I'm not a big believer in dowsing, but groundwater is my day job, so your mileage may vary!)