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-towater (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.