TTHM Concentration in Community Water Metadata
- metadata
- idinfo
- citation
- citeinfo
- origin: New Mexico EPHTN Project Manager
- pubdate: 20230718
- title: TTHM Concentration in Community Water
- onlink
- descript
- abstract: These total trihalomethanes (TTHM) concentrations (measured as the sum concentration of chloroform, bromodichloromethane, dibromochloromethane, and bromoform in micrograms of TTHMs per liter of water or mcg/L) drinking water quality sample data for New Mexico community water systems (CWS) contain the information needed to calculate Environmental Public Health Tracking (EPHT) annual and quarterly drinking water quality mean and maximum concentration measures for each system or the for state by the number of CWS or the number of people served. The data are derived from New Mexico Safe Drinking Water Information System (SDWIS) database, 1999-2022. That dataset contains records for active CWS (active for the prior year at the time of extract from the state database, typically in February or March for the prior year’s sample data, e.g. March 2018 for the 2017 data). A CWS is a public water system that serves year-round residents of a community, subdivision, or mobile park that has at least 15 service connections or an average of at least 25 residents. These CWSs are a subset of all NM public water systems (PWS). Other water systems are not included. The number of CWS varies from year to year, by a few, typically 2-3. There have been 631 CWS active at one time or another and in 2022 there were 561 active CWSs.
The New Mexico Environment Department, Drinking Water Bureau, collects and maintains the original data.
Note, that on December 8, 2003, the Environmental Protection Agency (EPA) established a drinking water standard or Maximum Contaminant Level (MCL) for TTHM of 80 micrograms per liter (80 mcg/L) or 80 parts per billion (80 ppb) to protect public health. The initial monitoring requirements were established for TTHM in 1998 and by 2005 the compliance monitoring framework was set for all CWSs. The New Mexico Environment Department, Drinking Water Bureau, collects and maintains the original data.
- purpose: This dataset was created as part of the Environmental Public Health Tracking Network (EPHTN) drinking water quality measures. It is intended to provide researchers, public health professionals, and the public with summary information on TTHM concentrations in community drinking water in New Mexico. The EPHT Content Workgroup Water Team identified initial contaminants of concern for the national EPHT program, identified nationally consistent data sources, and developed nationally consistent indicators and measures. This dataset can be used to calculate the nationally consistent measures for the New Mexico EPHT Program.
- supplinf: Treatment of non-detects: Sample results for TTHM with concentrations less than the detection limit (but non-zero) have been replaced with a value equal to 0.5 the detection limit for the analytical method used. If a detection limit was not available from the SDWIS dataset or reported as zero, an estimate of the detection limit and/or a standard analytical method detection limit was applied. Missing data: the current format of the NCDMs annual dataset contains one record for quarterly- or annually-aggregated data and each compliance sample taken to test for TTHM among active CWS for the years 1999-2022. If samples were not collected to test for TTHM during a given quarter or year, there would be no record in the dataset. Consequently, when records are compiled for comparisons by CWSs, it may appear that the dataset has missing data. In order to mitigate the issue of “missing data” for cases when the data are in fact not missing, the carry forward procedure has been implemented. Under this procedure, if samples were not collected to test for TTHM during a given year because the system (1) was not required to take a compliance sample during that particular period or (2) the system failed to collect the sample from the required location and/or collect the sample during the compliance month thus resulting in a non-sampling violation or (3) received a sampling wavier from the state for reduced frequency of monitoring based on low analytical results, then the last quarter or year sampling result value was carried forward together with the year of the actual sample collection information. However, CWSs that have come online after the start date of the extraction query will have missing values up until the system became active. Thus, missing values may be because the water system was not yet active and current. These “missing values” are labeled as “not sampled”.
Drinking water wholesalers that have interties and sold their water to the CWS having a retail population were not included in the dataset even when SDWIS captured this information accurately and completely. Each importing CWS was attributed with wholesalers’ applicable sampling results data. There are no other values missing for reasons beyond what the state's or EPA's monitoring framework and the structure of the EPHT NCDMs creates. The data prior to 2005 may have limited quality.
- timeperd
- timeinfo
- rngdates
- begdate: 19990101
- begtime
- enddate: 20221231
- endtime
- current: Publication Date
- status
- progress: Complete
- update: Annually
- spdom
- bounding
- westbc: -109.05017700000001
- eastbc: -103.00206900000001
- northbc: 37.000292999999999
- southbc: 31.332173999999998
- keywords
- theme
- themekt: NONE
- themekey: TTHM; 2950; Environmental hazard; Environment; Water quality; Public water system; PWS; Community water system; CWS; ground water; State drinking water data set; National drinking water data set; Safe drinking water act; SDWA; safe drinking water information system; SDWIS; MCL; MCL violations; Maximum Contaminant Level
- place
- placekt: FIPS 5-2 (State)
- placekey: NM, New Mexico, 35
- place
- placekt: FIPS 6-4 (County)
- placekey: New Mexico, NM, 35; 001 (Bernalillo), 003 (Catron), 005 (Chaves), 006 (Cibola), 007 (Colfax), 009 (Curry), 011 (De Baca), 013 (Dona Ana), 015 (Eddy), 017 (Grant), 019 (Guadalupe), 021 (Harding), 023 (Hidalgo), 025 (Lea), 027 (Lincoln),028 (Los Alamos), 029 (Luna), 031 (McKinley), 033 (Mora), 035 (Otero), 037 (Quay),039 (Rio Arriba), 041 (Roosevelt), 043 (Sandoval), 045 (San Juan), 047 (San Miguel), 049 (Santa Fe), 051 (Sierra), 053 (Socorro), 055 (Taos), 057 (Torrance), 059 (Union), 061 (Valencia)
- accconst: These data are publicaly available; No permission required.
- useconst: These data may not be used to identify single problematic water systems. To identify regulatory or compliance issues with single water systems contact the NMED-DWB. The principal county served variable designates the principal county in which the CWS is located as reported by the supplier; however, community drinking water system distribution areas may extend beyond county boundaries. Use of the principal county served variable to link drinking water data to health outcomes or other data should be made only with extreme precautions, after the implications of doing so are completely understood, and with fully and explicitly stating the limitations of the linkage. These data are aggregate summary measures of contaminant levels in finished water. They reflect the potential for population exposure but are not true exposure estimates; therefore they should not be used in any epidemiologic investigations of health outcome and environmental linkages. These data may not be used to identify any individual or residence who is receiving drinking water. In addition, the data prior to 2005 may have limited quality and as such should be used with caution.
No responsibility is assumed by the NM Department of Health (NMDOH) related to data and materials or how these data are represented by those who access this information. All users must read and fully comprehend metadata prior to data use.
- ptcontac
- cntinfo
- cntperp
- cntper: New Mexico EPHTN Project Manager
- cntorg: New Mexico Department of Health, Environmental Health Epidemiology Bureau
- cntpos
- cntaddr
- addrtype: Physical
- address: 1190 St. Francis Drive
- city: Santa Fe
- state: NM
- postal: 87505
- country: United States Of America
- cntvoice: 18888788992
- cntvoice
- cnttdd
- cntfax: 5058270013
- cntemail: DOH-EHEB@state.nm.us
- hours: 8:00 - 5:00
- cntinst
- secinfo
- secsys: None
- secclass: Unclassified
- sechandl: None
- native: SAS 9.4, water_pws_ann.sas7bdat and water_pws_qtr.sas7bdat
- dataqual
- logic: None
- complete: These data are complete with respect to CDC's NCDM requirements. This dataset contains only regulated community water systems, which were active at the time of the data extraction date from the state database (i.e., in March, 2022). All CWS taking compliance samples from January 1, 1999-December 31, 2022 are included in the dataset. Compliance samples collected by drinking water wholesalers that have interties with and sold to the CWS having a retail population are included within each importing CWS applicable sampling results data. Private, non-transient, and non-community water systems are not included in this dataset. Since 1998, under Stage I Disinfectants and Disinfection Byproduct Rule (DBPR), TTHM monitoring framework or water sampling frequency varies among water systems depending on the water source (ground or surface water), population of residents served (less than 500, 500 or greater but less than 10,000 and 10,000 and greater), number of treatment plants and levels of TTHM measured at location representing maximum residence time: (1) water systems using only ground water routinely sample with one water sample per treatment plant, and if serving at least 10,000 persons, then samples every quarter whereas those with smaller populations sample annually during the month with the warmest water temperature, (2) water systems using only ground water may reduce monitoring frequency to once a year at the location reflecting maximum residence time during the warmest water month of the year if serving at least 10,000 person and annual average TTHM concentration is less than or equal to the MCL or, if the systems serves less than 10,000, then samples are collected once every three years, (3) water systems using surface water and serving fewer than 500 persons routinely sample once a year at the location reflecting maximum residence time during the warmest water month of the year, (4) water systems using surface water and serving from 500 to under 10,000 persons routinely sample once per quarter per treatment plant, (5) water systems using surface water and serving from 500 to under 10,000 persons may reduce monitoring frequency to sample once per year per treatment plant at the location reflecting maximum residence time during the warmest water month of the year, (6) water systems using surface water and serving at least 10,000 persons routinely sample four times per quarter per treatment plant and (7) water systems using surface water and serving at least 10,000 persons may reduce monitoring frequency to sample once per treatment plant per quarter per year if annual average TTHM is half or less of the MCL. Stage I DBPR monitoring sunset September 30, 2013.
Beginning October 1, 2013, all CWSs became responsible for Stage 2 DBPR Compliance monitoring. Systems were required to evaluate their distribution system and identify the locations with high TTHM. Compliance with the maximum contaminant levels was calculated for each location in the distribution system. This approach, referred to as the locational running annual average (LRAA), differs from the Stage 1 requirements, which determine compliance by calculating the running annual average of samples from all monitoring locations across the system. Framework or water sampling frequency varies among water systems depending on the water source (ground or surface water), population of residents served (less than 500, 500 or greater but less than 10,000 and 10,000 and greater). CWS serving at least 100,000 began compliance monitoring April 1, 2012. Systems were required to take individual TTHM samples at locations with the highest TTHM concentrations. Trihalomethanes typically continue to form in the distribution system over time so the highest concentration of these are most often found at the outermost edges of a distribution system (furthest from the water treatment facility) where the oldest water is found. Thus, this is where sampling locations for TTHMs are most appropriately located (the Maximum Retention Time or MRT Site). CWSs serving 50,000 to 99,999 began compliance monitoring on October 1, 2012. CWS serving 49,999 and fewer began monitoring on October 1, 2013
- lineage
- procstep
- procdesc: This dataset was created by extracting data for non-transient CWSs in NM, which were active for the entire year during 1999-2022 or portion therein. A CWS is a public water system that serves year-round residents of a community, subdivision, or mobile home park that has at least 15 service connections or an average of at least 25 residents. Sample results are limited to samples taken between January 1, 1999 and December 31, 2022. This dataset accommodates summary-level measures of water TTHM concentrations. This dataset contains information on CWS representing all 33 NM counties. The data extracted from NMSDWIS were processed using the Centers for Disease Control and Prevention (CDC) Drinking Water Quality Nationally Consistent Data and Measures (NCDMs) How-To Guide within the Environmental Public Health Tracking Network, version 2, January 19, 2022.
- procdate: 20220405
- procstep
- procdesc: NM EPHT receives drinking water system data for community water systems (CWS) from the NM Environment Department Safe Drinking Water Information System (SDWIS). Data are received in MS Excel spreadsheets, with location coordinates in four different datums for CWS business address: three geographic and one unknown. Populated place locations are captured, where possible, with a matching merge with 2018 version of USGS Geographic Names Information (NAD83) by feature name.
- procstep
- procdesc: NMEPHT data queried through nmtracking.org (NMTracking) result in query-specific data sets that are community water system specific or statewide.
- eainfo
- overview
- eaover: The dataset contains quarterly average and annual average and maximum concentrations for TTHM. The fields in the dataset are: PWSIDNumber, TimePeriod, Analyte (Nitrate), AggregationType (mean or maximum), Concentration, and ConcentrationUnits. The dataset also contains fields describing Community Water Systems (CWS) derived from an inventory file of CWS qualifying Public Water Systems such as number of connections and approximate number of people served.
- eadetcit: Data dictionary (last revised: January 19, 2022) is available by contacting the NM EPHT Program at http://nmtracking.org or DOH-EHEB@state.nm.us.
- distinfo
- distrib
- cntinfo
- cntperp
- cntper: New Mexico EPHTN Project Manager
- cntorg: New Mexico Department of Health, Environmental Health Epidemiology Bureau
- cntpos
- cntaddr
- addrtype: Physical
- address: 1190 St. Francis Drive
- city: Santa Fe
- state: NM
- postal: 87505
- country: United States of America
- cntvoice: 18888788992
- cntvoice
- cnttdd
- cntfax: 5058270013
- cntemail: DOH-EHEB@state.nm.us
- hours: 8:00 - 5:00
- cntinst
- resdesc: TTHMCommunityWater (.xml).
- distliab: In preparation of data, every effort has been made to offer the most current and correct data possible. Nevertheless, inadvertent errors in data may occur, specifically as far as the prior to 2005 data are concerned. The EPHTN disclaims any responsibility for data errors and accuracy of the information that may be contained within the SDWIS database. The EPHTN also reserve the right to make changes at any time without notice.
- custom: Distributed through the NM Environmental Public Health Tracking Network (EPHTN). The full dataset can be obtained by contacting the distributor listed in the contacts section.
- metainfo
- metd: 20230718
- metc
- cntinfo
- cntperp
- cntper: New Mexico EPHTN Project Manager
- cntorg: New Mexico Department of Health, Environmental Health Epidemiology Bureau
- cntpos
- cntaddr
- addrtype: Physical
- address: 1190 St. Francis Drive
- city: Santa Fe
- state: NM
- postal: 87502
- country: United States Of America
- cntvoice: 18888788992
- cntvoice
- cnttdd
- cntfax: 5058270013
- cntemail: DOH-EHEB@state.nm.us
- hours: 8:00 - 5:00
- cntinst
- metstdn: EPHTN Tracking Network Profile Version 3
- metac: None
- metuc: This information is provided by the Environmental Health Epidemiology Bureau (EHEB) of the New Mexico Department of Health. All users must read and fully comprehend metadata prior to data use.
