California Community Water Systems inventory dataset, 2011

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: CEHTP Science Team
Publication_Date: 20120406
Title:
California Community Water Systems inventory dataset, 2011
Online_Linkage:
Description:
Abstract:
This data set contains information about all Community Water Systems in California. Data are derived from California Office of Drinking Water (ODW) Water Quality Monitoring Database (WQMD, also know as Water Quality Inventory or WQI) and Permits, Inspection, Compliance, Monitoring, and Enforcement (PICME) database. The data set contains one record for each Community Water System (CWS) active for all or part of the latest reporting year. It includes additional detail about how many retail connections by each CWS, how many people are served by each CWS, and the approximate location of each CWS.
Purpose:
This data set contributes to the Environmental Public Health Tracking Network. The EPHT cooperative agreement states that all grantees must track and make available core environmental health tracking measures on the State and National EPHT Network, including data/information on key drinking water contaminants for regulated public water supplies, as defined through the Content workgroup process. The Content Workgroup Water Team identified contaminants of concern for the national EPHT program, identified nationally consistent data sources, and developed nationally consistent indicators and measures. This data set can be used to enumerate all Community Water Systems in California. Using the Public Water System ID Number, it can be joined with the sampling results dataset.
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20110101
Beginning_Time:
Ending_Date: 20111231
Ending_Time:
Currentness_Reference:
Publication Date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Once per year
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -124.409721
East_Bounding_Coordinate: -114.131208
North_Bounding_Coordinate: 42.009521999999997
South_Bounding_Coordinate: 32.53416
Keywords:
Theme:
Theme_Keyword_Thesaurus: NONE
Theme_Keyword: hazard
Place:
Place_Keyword_Thesaurus:
Place_Keyword: California,CA,06
Access_Constraints: none
Use_Constraints:
The geographic locations provided in this dataset were not verified for accuracy by State Primacy Agency officers or water system staff. The locations are provided and intended for diagrammatic and visualization purposes, such that the approximate location of the CWS service area can be described on a small scale map. These locations are not designed for large scale analyses and should not be used in linking to health data.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: CEHTP Science Team
Contact_Organization: CA Department of Public Health, CA Environmental Health Tracking Program
Contact_Position:
Contact_Address:
Address_Type: Mailing
Address:
850 Marina Bay Parkway, Bldg P, 3rd Floor
City: Richmond
State_or_Province: CA
Postal_Code: 94804
Country: United States Of America
Contact_Voice_Telephone: 5106203620
Contact_TDD/TTY_Telephone:
Contact_Facsimile_Telephone: 5106203720
Contact_Electronic_Mail_Address: data@cehtp.org
Hours_of_Service:
Contact Instructions:

Security_Information:
Security_Classification_System: none
Security_Classification: Unclassified
Security_Handling_Description: none
Native_Data_Set_Environment:
Relational Database Management System: SQL Server 2005 Filename: NCDM_inventory.xml
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Data_Quality_Information:
Logical_Consistency_Report:
The EPHTN Drinking Water Content Workgroup concluded that an inventory of active, community water systems years 1999 to most current must be compiled.  WQMD and PICME are coded logically to successfully ascertain active CWS, however, a small minority of active CWS only export drinking water to other CWS with a non-zero retail population. For this reason, the legal definition (i.e. serving 15 retail connections or 25 people, year-round) of a CWS was also used in populating the CWS inventory. 3044 CWS were enumerated by this logic.

CWS-specific population-served estimates are often inaccurate, because individual water systems are given 3 options for performing this calculation:  1. using the US Census and/or CA Department of Finance, 2, multiplying the number of service connections by 3.3, and/or 3. estimating the population served for single connections that provide service to multiple dwelling establishments, such as mobile home parks, apartments, prisons, and other institutional facilities with permanent residents.  As of October 18, 2011, according to PICME and reported through this dataset, the total CWS population served was 43,086,077, whereas the US Census reports the CA population in 2011 as 37,691,912. Moreover, estimates of public drinking water use by USGS and from the 1990 Census found that only 85-90% of the CA population is served by CWS. Statewide, this means that the population served estimate as reported by this dataset may be 20-25% higher than the true value.

Latitude and longitude coordinates to describe a representative location for CWS were found using 5 methods in the following priority: 1. centroid of service area polygon (LocationDerivationCode=SA; N=1222), 2. centroid of facility coordinate locations expected to be near the service area (LocationDerivationCode=MFL; N=1605), 3. centroid of principal city served coordinates and geocoded system headquarters address point (LocationDerivationCode=0; N=166), 4. principal city served coordinates (LocationDerivationCode=PCS; N=38), 5.  geocoded system headquarters address point (LocationDerivationCode=GSH; N=12).  The logic used for subsetting sampling station locations that are expected to be near retail populations was as follows: any active or combination groundwater sampling location (raw, treated, or untreated) was considered to be near the retail population served. Typically, groundwater systems lie in or very near the consuming population. For active, mixed and surface water sampling locations, only treatment plant sampling stations and distribution system sampling locations were used.
Completeness_Report:
By definition, this dataset does not include unregulated drinking water providers, namely private drinking water wells or very small systems or mutuals in which there are less than 15 retail connections and less than 25 year-round residents.

Latitude and longitude values could not be found for 1 CWS; This CWS was coded as missing -999.
Lineage:
Process_Step:
Process_Description:
CEHTP received comma-separated (CSV) PICME database from ODW (dated 10/18/2011) and imported SYSNUM1 (N=14241) table into SQL Server 2005. Principal county served was inferred from the first 2 digits of the PWSID.
Process_Date: 20120315
Process_Step:
Process_Description:
Developed SQL statement for creating CWS Inventory table.  Primary logic holds PICME_SYSNUM1.PWS_CLASS='C' and PICME_SYSNUM1.P_M_STATUS='A' and ((PICME_SYSNUM1.CONNECTIONS>=15 and PICME_SYSNUM1.POPULATION>0) or PICME_SYSNUM1.POPULATION>=25) to select only Community Water Systems that are Active and with either 15+ connections or 25+ population served, respectively.  The logic for determining optional Primary Source Code departs from EPA Surface Water Treatment Rule logic; If all the active sources contained in a water system are all of one source type (ie. GW, SWP, SW, GWP, GU, or GUP), then the system was attributed with that source type, otherwise it is attributed as missing. 3,044 system inventory records returned by this logic.
Process_Date: 20120315
Process_Step:
Process_Description:
Downloaded Geographic Names Information System (GNIS) feature types and codes from geonames.usgs.gov and extracted feature ID based on joining the the county FIPS code and the city location name in PICME_SYNUM1 field. Merged the feature ID field into the inventory dataset. A code of -999 was reported for CWS that could not be attributed by this method (N=221).
Process_Date: 20120315
Process_Step:
Process_Description:
Exported current database state of PWS service areas (N=1,715 PWS) from CEHTP Drinking Water Systems Geographic Reporting Tool (http://ehib.org/water). Extracted centroid of CWS (N=1,222) and merged the corresponding latitude/longitude value into the inventory dataset using a LocationDerivationCode of 'SA'.
Process_Date: 20120315
Process_Step:
Process_Description:
For CWS not having service area centroids (N=1822), developed SQL statement for subsetting by PWSID individual sampling stations near service area using PICME_SOURCE table. Primary logic is as follows: union of following 2 where statements: 1. WATER_TYPE=G and ENTITY_INFO in (AR,AT,AU,IR,IT,IU,CR,CT,CU) and 2. WATER_TYPE in (S,M) and ENTITY_INFO in (AT,IT,CT,DR,DT). 1605 CWS were found with latitude longitude coordinates through this method. To ensure security, the reported centroids were rounded to the nearest hundredth (ie. accurate to ~1km) of a decimal degree.
Process_Date: 20120315
Process_Step:
Process_Description:
For the remaining CWS lacking latitude/longitude values (N=217), the water system headquarters address was geocoded using the CEHTP Centralized Geocoding Service.  These coordinates were averaged with corresponding CWS that had a principal city location (N=166). For the remaining CWS (N=51) that didn't have both a principal city and geocoded system headquarters available, the principal city alone was used (N=38), then lacking that, the geocoded system headquarters was used alone (N=12).
Process_Date: 20120315
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Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
The data set contains fields describing Community Water Supplies (CWS) such as number of connections and approximate people served.
Entity_and_Attribute_Detail_Citation:
Data dictionary is available from the National Tracking Program at http://www.cdc.gov/nceh/tracking.
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: CEHTP Science Team
Contact_Organization: CA Department of Public Health, CA Environmental Health Tracking Program
Contact_Position:
Contact_Address:
Address_Type: Mailing
Address:
850 Marina Bay Parkway, Bldg P, 3rd Floor
City: Richmond
State_or_Province: CA
Postal_Code: 94804
Country: United States Of America
Contact_Voice_Telephone: 5106203620
Contact_TDD/TTY_Telephone:
Contact_Facsimile_Telephone: 5106203720
Contact_Electronic_Mail_Address: data@cehtp.org
Hours_of_Service:
Contact Instructions:

Resource_Description:
Distribution_Liability:

Custom_Order_Process:

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Metadata_Reference_Information:
Metadata_Date: 20120315
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: CEHTP Science Team
Contact_Organization: CA Department of Public Health, CA Environmental Health Tracking Program
Contact_Position:
Contact_Address:
Address_Type: Mailing
Address:
850 Marina Bay Parkway, Bldg P, 3rd Floor
City: Richmond
State_or_Province: CA
Postal_Code: 94804
Country: United States Of America
Contact_Voice_Telephone: 5106203620
Contact_TDD/TTY_Telephone:
Contact_Facsimile_Telephone: 5106203720
Contact_Electronic_Mail_Address: data@cehtp.org
Hours_of_Service:
Contact Instructions:

Metadata_Standard_Name: EPHTN Tracking Network Profile Version 1.2
Metadata_Access_Constraints: none
Metadata_Use_Constraints:
none
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