Document ID: EPA-HQ-OPP-2014-0181-0014
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2014-10-03T04:00Z

DATA FIELDS IN THE WELL INVENTORY DATABASE

FIELD—Name—Description. Linked fields are shown by color fills

WELL-- Well Number -- The well number is a 16 digit field used as the
primary unique identifier in the well inventory database and is base on
the county, township, range, section, tract, sequence number for the
tract and meridian.  Each well must have a unique well number. This
number is considered “confidential” and along with the latitude and
longitude, requires a non-disclosure agreement to obtain.

WELL_KEY-- is a security key used for public distribution of well
information.  DPR does not release geographical information for any DHS
wells and only releases township/range/section information for DPR
wells.  Therefore, the WELL_KEY becomes the unique identifier for any
public or private agency requesting data.

COMTRS--County-Meridian-Township Range Section—The approximately
one-mile section of land where the well is located as defined by the
township-range-section system. This field can be derived from the well
number and is releaseable to the public. For example, a section in
Fresno County would be 10M14S17E31.

AGENCY-- Sampling Agency-- A four digit field with a character code
specifying the agency which performed the study.

ANAME—Name-- of the agency doing the study (may be up to 100
characters long).

SDATE-- Sample Date-- A date field used to note the date the sample was
taken.  The complete sample date is coded using characters in the format
DD-MON-YYYY.

NCHEM-- Chemical Code-- NCHEM is a five digit numeric field specifying
the chemical analyzed.  Results of analyses for pesticide active
ingredients, whether registered for use in California, or not, are
entered into the well inventory.

CHNAME—Chemical name—chemical name of the chemical analyzed. (may be
up to 150 characters long)

STYPE-- Sample Type--A one digit field with a character code specifying
descriptive analytical information for each analysis based on all the
analytical results for a particular well and chemical during that study.
The code is one of the following:

   I,INITIAL DETECTION SAMPLE NOT CONFIRMED                             
                                

   B,INITIAL DETECTION SAMPLE WITH FURTHER QUALITATIVE OR QUANTITATIVE
ANALYSES ALL NEGATIVE RESULTS     

   Q,INITIAL DETECTION SAMPLE WITH FURTHER ANALYSES                     
                                

   C,INITIAL DETECTION SAMPLE CONFIRMED BY DATA SOURCE AGENCY           
                                

   M,INITIAL DETECTION SAMPLE QUALITATIVELY CONFIRMED                   
                                

   P,INITIAL DETECTION WITH FURTHER QUANTITATIVE AND QUALITATIVE
ANALYSES                                

   D,SPLIT SAMPLE METHOD-DIFFERENT  LAB-DIFFERENT                       
                                

   E,SPLIT SAMPLE METHOD-SAME  LAB-DIFFERENT                            
                                

   F,SPLIT SAMPLE METHOD-DIFFERENT  LAB-DIFFERENT                       
                                

   G,SPLIT SAMPLE METHOD-SAME  LAB SAME                                 
                                

   H,REPLICATE SAMPLE METHOD-DIFFERENT LAB-SAME                         
                                

   J,REPLICATE SAMPLE METHOD-DIFFERENT  LAB-DIFFERENT                   
                                

   K,REPLICATE SAMPLE METHOD-SAME  LAB-DIFFERENT                        
                                

   L,REPLICATE SAMPLE METHOD-SAME  LAB-SAME                             
                                

   A,AVERAGED RESULT                                                    
                                

   N,SINGLE NON-DETECTED                                                
                                

   O,SINGLE RESULT                                                      
                                

   R,ROUTINE ONGOING                                                    
                                

   S,SPLIT SAMPLE                                                       
                                

   -,NOT SPECIFIED                                                      
                                

   Y,SPLIT  REPLICATE SAMPLE  METHOD-SAME  LAB-DIFFERENT                
                                

   T,INITIAL DETECTION SAMPLE  ANALYZED FOR MULTIPLE COMPOUNDS          
                                

   U,UNCONFIRMED DETECTION SAMPLE                                       
                                

   X,NEGATIVE DETECTION SAMPLE                                          
                                

   9,TEMPORARY DHS STYPE                                                
                                

   V,UNEQUIVOCAL DETECTION METHOD USED                                  
                                

 

CONC-- Chemical Concentration--A nine-digit numeric field with three
decimal places.  The chemical concentration is the amount in parts per
billion (ppb) of a chemical. Non-detect, trace, and concentrations
reported that are below the minimum detection level are coded as zero,
‘0’.  

MDL-- Minimum Detection Level --This field specifies the minimum
concentration (ppb) detectable by the analytical lab and method for each
analysis.  It is coded the same way as the chemical concentration field.

LAB-- Analyzing Lab --A four-digit field specifying the lab that
performed the chemical analysis. 

LABNAME—Name-- of the lab that performed the chemical analysis. (may
be up to 100 characters long)

METHOD--Method --A one character field with a character code specifying
the type of methodology used.    The code letter is one of the
following:  

‘E’ 		method developed by the USEPA, 

‘I’ 		method developed in-house by an analytical lab, 

‘O’ 		other method,  

‘-’ 		analytical method not reported

ADATE-- Analysis Date –A date field used to note the date the sample
was analyzed.  The complete analysis date is coded using the format
DD-MON-YYYY.  

APFILE-- File Name --A four digit field with a character code assigned
based on the submitting agency.  EM studies include apfiles Z###
(4-section surveys), GW## (ground water protection list monitoring) and
BE## (Bentazon monitoring).  Apfile codes for data submitted by outside
agencies include RB## (Regional Board), and WR## (Department of Water
Resources).  Typically a single apfile corresponds to a single study.

RPT_YR-- Report Year –A four-digit numeric field.  The report year
code is the year the data will be summarized in a report.

WATD-- Water Depth --A six-digit numeric field with one decimal place
specifying the depth-to-water (feet) in the well at the time of
sampling. (most wells in our database do not have this information.)

DEPTH-- Well Depth --A five-digit numeric field with one decimal place
specifying the depth of the well in feet. (many of the wells in the
database do not have this information.)

CODE-- Well Code--The well code is a one-digit field with a character
code specifying the use of the well.  Use the following codes and
descriptions to determine the most appropriate code.

‘A’	Unused well (corresponds to USGS well code ‘U’).  Water is
not being removed from the site for one of the purposes described below.
 A test hole, oil or gas well, recharge, drainage, observation, or
waste-disposal well will be assigned to this category.

‘B’	Both I and D

‘C’	Community well

‘D’	Domestic well (private residence)

‘F’	Both D and Y

‘G’	Both D and R

‘H’	D, I, and R

‘I’	Irrigation or agricultural

‘L’	Large water system (more than 200 service connections)

‘M’	Municipal and irrigation

‘N’	Non-community (schools, hospitals, restaurants, filling
stations, parks, campgrounds)  

‘R’	Stock - watering of livestock  (corresponds to the USGS well
code ‘S’)

‘S’	State small water system (less than 200 service connections)

‘T’	Test, monitoring, or observation well

‘U’	Unknown type of well

‘X’	Irrigation and industrial

‘Y’	Industrial

‘W’	Dewatering well (corresponds to the USGS well code ‘D’). 
Dewatering wells are described by USGS as water that is pumped from a
dewatering well to dewater a construction or mining site, or to lower
the water table for agricultural purposes.  A dewatering well differs
from a drainage well (U) that is used to drain surface water
underground.  If water is withdrawn from a well in order to provide
drainage by lowering the water table, DPR well code ‘D’ is assigned,
although the water may be discharged into an irrigation ditch and
subsequently used to irrigate land

‘X’	Irrigation and Industrial well

PORN-- Point or Non-Point-- The point or non-point source field is a one
character field specifying the determination of the cause of
contamination.  The PORN field will contain one of these five codes:

‘-’(dash) 	Where concentration =0 (non-detect) or where a
determination was not made for a positive detections (e.g. DBCP). Also
used where only one positive well was found during a four-section
survey.

‘P’	Point source. Detection reported as point source by another
agency, or determination made by EM that residues were likely the result
of point-source contamination (e.g. xylene detected with other gasoline
components).

‘N’	EM determined that residues in the well were the result of
legal, agricultural use as stated in a memo. Triggering detections of
verified detections of the same chemical are also designated as ‘N’

‘I’	Verified detection by EM, currently under investigation. After
determination, this field is updated to P, N, C, or -.

‘C’		Detection investigated by EM and determined to be due to poor
well construction.

STATUS-- Status --A one-digit field used to describe specific criteria
of an analytical result based on the study, well, chemical, and summary
year.  This field is used to determine ‘verified’ detections.  The
codes assigned are one of the following:

‘N’ 	non-detect (concentration=0)

‘P’ 	confirmed detection (2 or more positive detections during the
same study/well/chem/sy)

or wells where the stype is 'V'.

‘E’ 	Estimated value reported. Accurate quantification was not
available. Typically the value is below the Reporting Limit.

‘U’ 	unconfirmed detection (only 1 positive detection during the
same study/well/chem/sy)

‘X’ 	positive detection analyzed before 1987

CO-- County --A two-digit field with a character code specifying the
county in which the well is located.  This code is the same as the first
two digits of the well number.

CONAME—County Name—Name of the county where the well is located.

DNOTE-- Notes --A 60-digit character field for any special circumstances
or unusual things about a record. It is also used to state information
about incomplete sampling or analysis dates. 

METHOD_NOTE-- Method Note --A 40-digit character field for additional
information about the analytical methodology.