Wells and Septic Systems in the LWQD, Gallatin County, Montana

Author:  Steve Custer, Earth Sciences, Montana State University, Bozeman, MT 59717-3480
Data Compiled by:  Andrea Wright, Daryl Chipman, Luke Lohmuller, Steve Custer, Bob Snyder, and Julie LaBranche.
(Last modified 15 June 2000; 02 January 20010)

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Example Questions the Database Can Answer

1.  Where are wells that can be located on a map (Geocode, and GWIC)
2.  Where are septic systems that can be located on a map
      (Geocode, and Gallatin Department of environmental Health)
3.  How many wells are near the area of interest?
4.  How many septic systems are near the area of interest?
5.  When was the site built (Geocode, Well, Septic)?
6.  Where are the old septic systems?

There are 4 themes which show where wells and septic systems are in the Local Water Quality District (LWQD) in Gallatin County, Montana:

NOTE:  THERE ARE NO STATIC IMAGES AVAILABLE FOR THIS WEB PAGE.

  1. Wells (7).  This theme shows all locations where DOR Geocode or GWIC show a well and the location could be identified on the Gallatin County Road Book.
  2. Septic (8).  This theme shows all locations where DOR Geocode or the GCDEH indicate a septic system and the location could be identified on the Gallatin County Road Book.
  3. Well or Septic.  This theme shows all locations where DOR Geocode or the GCDEH indicate a septic system and the location could be identified on the Gallatin County Road Book.
  4. Well-Septic Score.  A point with a well has the attribute 7 and a point with a septic system has the attribute 8.  If a point has both attributes, the attributes can be summed to 15, if a point has a well and no septic system indicated the sum of 7 and 0 is 7, and if a point has a septic system and no well the score is the sum of 8 and 0 or 8.  Thus the locations of well and septic, just well and just septic can be identified.
The data comes from four sources:
1.  The geocode comes from the CAMAS data base maintained by the Montana Department of Revenue (DOR).  The DOR data base includes information on property address, date built and utilities present.  Utilities include well, septic system, public and community water, public and community septic systems, and Gas. If the point cannot be located the point is not digitized.
 2.  Well location data  is available from the Montana Ground-Water Information Center.
 3.  Septic system location data is available from the Gallatin County Department of Environmental Health (GCDEH).
The GCDEH data is in the septic permit file.
 4.  Gallatin County Road Book Dots.
The Gallatin County Road Book shows street addresses sections, subdivisions, lots and blocks.  Each structure is shown by a dot.  If there is a dot but no septic, well, or geocode data, then the dot was digitized without any attribute data.
Duplicate points do not have unique locations.  The well-septic database assumes only one location for each address in the road book.

About the Data This map shows where wells and septic systems are in the Local Water Quality District (LWQD) in Gallatin County Montana.  The data comes from four sources:
 1.  The CAMAS data base maintained by the Montana Department of Revenue (DOR) The DOR data base includes information on property address, date built and utilities present.  Utilities include well, septic system, public and community water, public and community septic systems, and Gas.  DOR sites are identified with a unique Geocode. If the geocode location could be identified based on address or subdivision lot and block the point was digitized from the 1995 Gallatin County Road Book by coordinating section corners with the Gallatin County Public Land Survey System (PLSS) data  and associated relevant permit data was attached.  If the point cannot be located the point is not digitized.
 2.  Well location data available from the Montana Ground-Water Information Center.  Again, if a well could be located based on address or subdivision, block and lot, the point was entered and data regarding the M-Number or GWIC identification number was added as was date drilled.  The point  was digitized from the 1995 Gallatin County Road Book by coordinating section corners with the Gallatin County Public Land Survey System (PLSS) data  and associated relevant permit data was attached.
 3.  Septic system location data available from the Gallatin County Department of Environmental Health (GCDEH).
The GCDEH data is in the septic permit file.  If the septic permit location could be identified based on address or subdivision lot and block the point was digitized on the 1995 Gallatin County Road Book by coordinating section corners with the Gallatin County Public Land Survey System (PLSS) data  and associated relevant permit data was attached.
 4.  Gallatin County Road Book Dots.
The Gallatin County Road Book shows street addresses sections, subdivisions, lots and blocks.  Each structure is shown by a dot.  If there is a dot but no septic, well, or geocode data, then the dot was digitized from the 1995 Gallatin County Road Book by coordinating section corners with the Gallatin County Public Land Survey System (PLSS) data and digitizing the point without any attribute data.

If more than  septic permit or well identification number (M-Number) exists for an address, this number is simply recorded as a multiple number for that point and no new point is “spawned”.  As a result the duplicate points do not have unique locations.  The well-septic database assumes only one location for each address in the road book.  Multiples are recorded but not given unique point locations.  Information about whether there is a well or septic system present is recorded, but detailed information about well properties or septic properties are not provided.  Detailed attribute data regarding wells can be found in the well coverage.  Not all points show either a well or a septic system.  Each structure indicated on the road book was recorded regardless of whether there is well or septic system information present.  In summary, the presence or absence of a well and/or septic system is recorded and duplicates or multiples at a site are ignored.

Summary of the four files welsep, welfnl, sepfnl, geocshp, and their differences:  (There are two primary differences between the welsep and the coverages  named geocshp, welsep and septicfnl.  First, the welsep file contains information drawn from three sources Department of Revenue Geocode database (well and septic data); the Montana Bureau of Mines and Geology Ground Water Information System (wells); the Gallatin County Septic Permit database (septic system).  These data are drawn together so that data from multiple sources can be assessed at the same time.)  If multiple wells, geocodes, or septic systems are listed at a site, only one point is given, but there are multiple columns for other septic system, well number, or geocode unit number at that point.

Welsep.shp Metadata
Welfnl.shp Metadata
Sepfnl.shp Metadata
Geocshp.shp Metadata

Alternatively, there are three separate geocode, well, and septic data bases (geocshp, welfnl, and septicfnl): these databases have had the locations where multiple geocodes wells or septic systems are indicated at a single site moved arbitrarily located several m from the first point so that each has a unique point location.  This information also allows one to explore the data base from different sources and the data from that source without dealing with the information from the other sources. (Although the geocode (parcel ID without the county number and the A97) is reported on all three data bases so that there is a common code.

The attached table indicates the meaning of each item in the attribute table for  the well and septic point coverage.