The first step in assessing the feasibility of drilling a viable well on a particular lot is to obtain driller's logs for existing wells on nearby developed properties. The Municipality of Anchorage (), Development Services Department (DSD) has microfiche records for most of the residential wells that have been drilled since 1975. Their office is located at 4700 Bragaw Street (907-343-7904), and is open to the general public Monday through Friday from 7:00am to 4:30pm. They also have a website containing most of these records accessable 24 hours a day (link below). Other sources for well information are the State of Alaska, Departments of Natural Resources (DNR) and Environmental Conservation (), as well as the U.S. Geological Survey. The pertinent information to obtain is the total depth of the well and the production rate. Obviously, if all of the adjacent lots have deep wells and low production, you should expect to find similar conditions on your lot. The same applies if all of the neighboring wells are shallow and high producing. Remember, the characteristics of the neighboring wells are only an indicator, and not a guarantee of what you will encounter. There are odd cases where a well on one lot may be high producing, and the well on the neighboring lot produces virtually no water at all.
In addition to reviewing the MOA records, it is recommended that you talk to a well driller who has experience with wells in the vicinity of your lot. Your realtor and/or your engineer can often provide you additional information on wells in the area.
Another factor to consider is whether there is a suitable location on the lot to place the well. Per Municipal regulation, a private well must meet all of the following seperation distance requirements:
- Private sewer service line: 25 feet
- Curtain drain (subsurface drain used to lower the water table): 25 feet
- Fuel storage tank: 25 feet
- Public sewer line: 75 feet
- Public sewer manhole or cleanout: 100 feet
- Septic tank or drainfield: 100 feet
- Animal feet lots, shelters, and containment areas (such as a horse corral): 50 feet
- Solid waste holding tank: 75 feet
- Other sources of potential contamination (this is not well defined): 75 feet
- Manure/Excrement Storage: 100 feet
In addition, the well cannot be positioned so that it would make any adjacent lot undevelopable. Your engineer or driller can identify areas on the property that are suitable for placement of the well.
Well Production Requirements:
Per Municipal regulations, a well must be capable of producing at least 150 gallons per day per bedroom. This corresponds to the following minimum flow rates:
- Five (5) bedrooms: 0.52 gallons per minute = 750 gallons per day
- Five (4) bedrooms: 0.42 gallons per minute = 600 gallons per day
- Five (3) bedrooms: 0.32 gallons per minute = 450 gallons per day
- Five (2) bedrooms: 0.22 gallons per minute = 300 gallons per day
These minimum flow rates have been established to meet only household uses and do not account for watering lawns/gardens, washing cars, or filling your new king size Jacuzzi tub. Consequently, if the flow rate of the well meets only minimum standards, it may be necessary to install water storage tanks, which serve as a reservoir to supplement the well production during peak flow requirements. It is common for residential water systems with low producing wells to have 500-1000 gallons of water storage. These tanks are often located in a crawl space or in the garage. A storage tank, the supplemental jet pump, and the associated controls can add several thousand dollars to the water system cost.
Wells which do not meet the aforementioned minimum flow standards must be equipped with a water storage system. Per the 1998 Municipal well ordinance, if the flow rate is less than the required amount, but greater than 150 gallons per day, a 500 gallon storage tank is required. If the daily productions of the well is less than 150 gallons per day, a 1000 gallon storage tank is required.
The primary reason for the storage tank is to allow for potable water to be delivered to the house on an as-needed basis. There are several companies that deliver potable water, typically charging a fee based upon the number of gallons purchased. Clearly, the objective is to select a lot on which there is a high probability of drilling a well that produces adequate water so that water delivery/purchase is not necessary. In areas where the chance of drilling a "decent" well is somewhat uncertain, you may want to consider requesting the well be drilled, at the sellers expense, prior to purchasing the lot, with agreement that you will reimburse them for it at closing, assuming the production is adequate. Bear in mind that most sellers will not be receptive to this idea. Nonetheless, by heeding this advice, you can be certain that the land that you are purchasing has a viable groundwater source.
Well Production Can Vary Seasonally:
It is important to know that well production can vary seasonally, sometimes quite dramatically. Wells will typically produce better in the late spring, after the aquifer is recharged by the snowmelt, and in the late fall (mid October) after the aquifer is recharged from the August/September rains. It is also possible that well production will decline in the middle of winter, because the aquifer is not being recharged by melting snow or rainfall. Given these facts, it is reasonable to assume that if a well barely meets minimum flow standards in late spring, there is a good chance that it's production will be below minimum standards in January and February. In short, when evaluating neighboring wells, note the time of year the well was tested.
Well Construction Costs:
Well depths will typically vary, based upon location, between 40 and 600 feet. The cost of drilling a well and installing the other components necessary for the water system are summarized as follows (a well driller should be contacted regarding specific costs):
- Construction of road and pad for the well driller to access the site and set up the drilling rig: If a road has to be built, numerous trees cleared, or a significant quantity of snow plowed, in order to access the well area, there will be additional charges to the drilling costs: Charges will typically range from $1,000 to $2,500.
- Well Drilling: $38 per foot (2007 cost).
- Purchase/install pump, pressure tank, and controls: Will vary with depth of the well, but assume an average cost of $1,500 to $2,500.
- Run the water service line from the well to the house. Ideally, the well should be as close as possible to the house so as to minimize the length of the water line run (which is buried 10 feet deep). $30 per foot of water line (2007 price), assuming bedrock is not present. In areas with shallow bedrock it may be necessary to blast the trench for the water line excavation.
- Water storage system (if necessary): Approximately $2,500.