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Monitoring Unregulated Drinking Water Contaminants

Reporting Requirements for the Fourth Unregulated Contaminant Monitoring Rule (UCMR 4)

Laboratories responsible for sample analysis under the fourth Unregulated Contaminant Monitoring Rule (UCMR 4) post data to EPA’s web-based Safe Drinking Water Accession and Review System (SDWARS) on behalf of Public Water Systems (PWSs). Users (including PWSs that wish to review/approve data posted by their laboratories) access SDWARS through the Central Data Exchange (CDX), EPA's electronic reporting system. A SDWARS instruction document is available to assist PWSs and laboratories with navigating the database and completing their reporting requirements.

PWSs that are subject to UCMR are also subject to the Consumer Confidence Report (CCR) and the Public Notification (PN) rules. The CCR rule requires that community water systems (CWSs) report monitoring results when unregulated contaminants are detected (40 CFR 141.151). To obtain your CCR reports you should contact your water supplier or you may find information for how to obtain a copy of the CCR in your water bill. The PN rule requires that water systems notify the public that the results are available (40 CFR 141.207). Please refer to the CCR rule and the PN rule for further information.

On this page:

Key reporting dates

Deadlines for reporting prior to monitoring

  • Ground water PWSs serving more than 10,000 people that wish to monitor from representative entry points to the distribution system (EPTDS) using the flexibility described in the rule, must submit either:
    • a copy of an approved ground water representative monitoring plan (GWRMP) from a prior UCMR cycle, or
    • a new, proposed GWRMP
By December 31, 2017:
  • PWSs serving more than 10,000 people are required to report contact information to SDWARS
  • PWSs serving more than 10,000 people are required to review and if necessary revise:
    • sampling location information
    • monitoring schedule in SDWARS
After December 31, 2017:
  • PWSs serving more than 10,000 people are required to notify EPA:
    • of sampling location and inventory changes
    • if unable to sample according to the established schedule

Reporting monitoring results

  • Within 120 days from sample collection: Laboratories post monitoring results to EPA's electronic reporting system, SDWARS.
  • Within 60 days from lab posting of data: PWSs serving more than 10,000 people review and approve data.

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Questions and answers on reporting

What do water systems serving 10,000 or fewer people ("small systems") need to do?

Small water systems selected for monitoring will need to collect samples for EPA, using sampling kits and following sampling instructions provided by the Agency's support contractor. EPA will arrange for sample analysis and will review monitoring results for small PWSs.

What do water systems serving more than 10,000 people ("large systems") need to do?

Large systems will need to do the following:

  • Review instructions on accessing SDWARS through CDX
  • Report contact information to EPA through SDWARS
  • Review and, if necessary, revise their monitoring schedules established by EPA in SDWARS
  • Provide inventory information for each applicable sampling location
  • Monitor for unregulated contaminants per the established schedule

In addition, PWSs are responsible for approving and submitting analytical results to EPA using SDWARS. PWSs will have 60 days after a laboratory posts data to act on their monitoring data. If the PWS does not act on their data within those 60 days, EPA will consider the data approved by the PWS and available to EPA for review and public release. After EPA review, UCMR 4 data reside in EPA's National Contaminant Occurrence Database (NCOD) and on UCMR's occurrence data page.

What do laboratories need to do?

Laboratories must be approved by EPA prior to analyzing and reporting results to SDWARS. Laboratories can only post data for methods for which they have gained EPA approval. To gain EPA approval, laboratories must successfully complete the process of UCMR's laboratory approval program.

Laboratories granted EPA approval are obligated to report their data to SDWARS within 120 days of sample collection. Instructions on submitting data can be found in SDWARS.

What do states need to do?

States will have an opportunity to review PWS data upon PWS approval. States can review data through SDWARS.

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Data elements for UCMR 4

Data element

Definition

1. Public Water System Identification (PWSID) Code

The code used to identify each PWS. The code begins with the standard 2-character postal State abbreviation or Region code; the remaining 7 numbers are unique to each PWS in the State. The same identification code must be used to represent the PWS identification for all current and future UCMR monitoring.

2. Public Water System Name

Unique name, assigned once by the PWS.

3. Public Water System Facility Identification Code

An identification code established by the State or, at the State’s discretion, by the PWS, following the format of a 5-digit number unique within each PWS for each applicable facility (i.e., for each source of water, treatment plant, distribution system, or any other facility associated with water treatment or delivery). The same identification code must be used to represent the facility for all current and future UCMR monitoring.

4. Public Water System Facility Name

Unique name, assigned once by the PWS, for every facility ID (e.g., Treatment Plant).

5. Public Water System Facility Type

That code that identifies that type of facility as either:
CC = consecutive connection
DS = distribution system
IN = source water influent
SS = sampling station
TP = treatment plant
OT = other

6. Water Source Type

The type of source water that supplies a water system facility. Systems must report one of the following codes for each sampling location:
SW = surface water (to be reported for water facilities that are served entirely by a surface water source during the twelve-month period).
GW = ground water (to be reported for water facilities that are served entirely by a ground water source during the twelve-month period).
GU = ground water under the direct influence of surface water (to be reported for water facilities that are served all or in part by ground water under the direct influence of surface water at any time during the twelve-month sampling period), and are not served at all by surface water during this period.
MX = mixed water (to be reported for water facilities that are served by a mix of surface water, ground water and/or ground water under the direct influence of surface water during the twelve-month period).

7. Sampling Point Identification Code

An identification code established by the State, or at the State’s discretion, by the PWS, that uniquely identifies each sampling point. Each sampling code must be unique within each applicable facility, for each applicable sampling location (i.e., entry point to the distribution system, source water influent or distribution system sample at maximum residence time). The same identification code must be used to represent the sampling location for all current and future UCMR monitoring.

8. Sampling Point Name

Unique sample point name, assigned once by the PWS, for every sample point ID (e.g., Entry Point).

9. Sampling Point Type Code

A code that identifies the location of the sampling point as either:
SR = source water taken from plant influent; untreated water entering the water treatment plant (i.e., a location prior to any treatment).
EP = entry point to the distribution system.
DS = distribution system sample.

10. Disinfectant Type

All of the disinfectants/oxidants that have been added prior to the entry point to the distribution system. Please select all that apply.
PEMB = Permanganate
HPXB = Hydrogen peroxide
CLGA = Gaseous chlorine
CLOF = Offsite Generated Hypochlorite (stored as a liquid form)
CLON = Onsite Generated Hypochlorite
CAGC = Chloramine (formed with gaseous chlorine)
CAOF = Chloramine (formed with offsite hypochlorite)
CAON = Chloramine (formed with onsite hypochlorite)
CLDB = Chlorine dioxide
OZON = Ozone
ULVL = Ultraviolet light
OTHD = All other types of disinfectant/oxidant
NODU = No disinfectant/oxidant used

11. Treatment Information

Treatment information associated with the sample point. Please select all that apply.
CON = Conventional (non-softening, consisting of at least coagulation/sedimentation basins and filtration)
SFN = Softening
RBF = River bank filtration
PSD = Pre-sedimentation
INF = In-line filtration
DFL = Direct filtration
SSF = Slow sand filtration
BIO = Biological filtration (operated with an intention of maintaining biological activity within filter)
UTR = Unfiltered treatment for surface water source
GWD = Groundwater system with disinfection only
PAC = Application of powder activated carbon
GAC = Granular activated carbon adsorption (not part of filters in CON, SCO, INF, DFL, or SSF)
AIR = Air stripping (packed towers, diffused gas contactors)
POB = Pre-oxidation with chlorine (applied before coagulation for CON or SFN plants or before filtration for other filtration plants)
MFL = Membrane filtration
IEX = Ionic exchange
DAF = Dissolved air floatation
CWL = Clear well/finished water storage without aeration
CWA = Clear well/finished water storage with aeration
ADS = Aeration in distribution system (localized treatment)
OTH = All other types of treatment
NTU = No treatment used
DKN = Do not know

12. Disinfectant Residual Type

Disinfectant residual type in the distribution system for each HAA sample.
CL2 = Chlorine (i.e., originating from addition of free chlorine only)
CLO2 = chlorine dioxide
CLM = Chloramines (originating from with addition of chlorine and ammonia or pre-formed chloramines)
CAC = Chlorine and chloramines (if being mixed from chlorinated and chloroaminated water)
NOD = No disinfectant residual

13. Sample Collection Date

The date the sample is collected, reported as 4-digit year, 2-digit month, and 2-digit day (YYYY/MM/DD).

14. Sample Identification Code

An alphanumeric value up to 30 characters assigned by the laboratory to uniquely identify containers, or groups of containers, containing water samples collected at the same sampling location for the same sampling date.

15. Contaminant

The unregulated contaminant for which the sample is being analyzed.

16. Analytical Method Code

The identification code of the analytical method used.

17. Extraction Batch Identification Code

Laboratory assigned extraction batch ID. Must be unique for each extraction batch within the laboratory for each method. For CCC samples report the Analysis Batch Identification Code as the value for this field. For methods without an extraction batch, leave this field null.

18. Extraction Date

Date for the start of the extraction batch (YYYY/MM/DD). For methods without an extraction batch, leave this field null.

19. Analysis Batch Identification Code

Laboratory assigned analysis batch ID. Must be unique for each analysis batch within the laboratory for each method.

20. Analysis Date

Date for the start of the analysis batch (YYYY/MM/DD).

21. Sample Analysis Type

The type of sample collected and/or prepared, as well as the fortification level. Permitted values include:
CF = concentration fortified; the concentration of a known contaminant added to a field sample reported with sample analysis types LFSM, LFSMD, LFB, CCC and QCS.
CCC = continuing calibration check; a calibration standard containing the contaminant, the internal standard, and surrogate analyzed to verify the existing calibration for those contaminants.
FS = field sample; sample collected and submitted for analysis under this rule.
IS = internal standard; a standard that measures the relative response of contaminants.
LFB = laboratory fortified blank; an aliquot of reagent water fortified with known quantities of the contaminants and all preservation compounds.
LRB = laboratory reagent blank; an aliquot of reagent water treated exactly as a field sample, including the addition of preservatives, internal standards, and surrogates to determine if interferences are present in the laboratory, reagents, or other equipment.
LFSM = laboratory fortified sample matrix; a UCMR field sample with a known amount of the contaminant of interest and all preservation compounds added.
LFSMD = laboratory fortified sample matrix duplicate; duplicate of the laboratory fortified sample matrix.
QCS = quality control sample; a sample prepared with a source external to the one used for initial calibration and CCC. The QCS is used to check calibration standard integrity.
QHS = quality HAA sample; HAA sample collected and submitted for quality control purposes.
SUR = surrogate standard; a standard that assesses method performance for each extraction.

22. Analytical Results—Sign

A value indicating whether the sample analysis result was:
(<) “less than” means the contaminant was not detected, or was detected at a level below the Minimum Reporting Level.
(=) “equal to” means the contaminant was detected at the level reported in “Analytical Result— Measured Value.”

23. Analytical Result—Measured Value

The actual numeric value of the analytical results for: field samples; laboratory fortified matrix samples; laboratory fortified sample matrix duplicates; and concentration fortified.

24. Additional Value

Represents the true value or the fortified concentration for spiked samples for QC Sample Analysis Types (CCC, EQC, LFB, LFSM and LFSMD). For Sample Analysis Type FS and LRB and for IS and surrogate QC Contaminants, leave this field null.

25. Laboratory Identification Code

The code, assigned by EPA, used to identify each laboratory. The code begins with the standard two-character State postal abbreviation; the remaining five numbers are unique to each laboratory in the State.

26. Sample Event Code

A code assigned by the PWS for each sample event. This will associate samples with the PWS monitoring plan to allow EPA to track compliance and completeness. Systems must assign the following codes:
SEC1, SEC2, SEC3, SEC4, SEC5, SEC6, SEC7 and SEC8 - represent samples collected to meet UCMR Assessment Monitoring requirements for cyanotoxins; where “SEC1” represents the first sampling period, “SEC2” the second period and so forth, for all eight sampling events.
SEA1, SEA2, SEA3 and SEA4 - represent samples collected to meet UCMR Assessment Monitoring requirements for the additional contaminants; where “SEA1” and “SEA2” represent the first and second sampling period for all water types; and “SEA3” and “SEA4” represent the third and fourth sampling period for SW and GU sources only.
27. Bloom Occurrence A yes or no answer provided by the PWS for each cyanotoxin sample event.
Question: Preceding the finished water sample collection, did you observe an algal bloom in your source waters near the intake?
YES = if yes, select all the YESs that apply:
  • YD = yes, on the day the UCMR cyanotoxin sample was collected
  • YW = yes, between the day the sample was taken and the past week
  • YM = yes, between the past week and past month
  • YY = yes, between the past month and past year
  • YP = yes, prior to the past year
NO = have never seen a bloom
28. Cyanotoxin Occurrence A yes or no answer provided by the PWS for each cyanotoxin sample event.
Question: Preceding the finished water sample collection, were cyanotoxins ever detected in your source waters near the intake and prior to any treatment (based on sampling by you or another party)?
YES = if yes, select all the YESs that apply:
  • YD = yes, on the day the UCMR cyanotoxin sample was collected
  • YW = yes, between the day the sample was taken and the past week
  • YM = yes, between the past week and past month
  • YY = yes, between the past month and past year
  • YP = yes, prior to the past year
NO = have never detected cyanotoxins in source water
NS = unaware of any source water cyanotoxin sampling
Select all that apply (i.e., all that were detected) if you answered YES to detecting cyanotoxins in source water:
  • MIC = Microcystins
  • CYL = Cylindrospermopsin
  • ANA = Anatoxin-A
  • SAX = Saxitoxins
  • OTH = Other
  • DK = do not know
29. Indicator Of Possible Bloom - Treatment A yes or no answer provided by the PWS for each cyanotoxin sample event.
Question: Preceding the finished water sample collection, did you notice any changes in your treatment system operation and/or treated water quality that may indicate a bloom in the source water?
YES = if yes, select all that apply:
  • DFR = Decrease in filter runtimes
  • ITF = Increase in turbidity in filtered water
  • ICD = Need for increased coagulant dose
  • TOI = Increase in taste and odor issues in finished water
  • IOD = Need for increase in oxidant/disinfectant dose
  • IDB = Increase in TTHM/HAA5 in finished water
  • OTH = Describe other changes
NO = no changes
30. Indicator of Possible Bloom – Source Water Quality Parameters A yes or no answer provided by the PWS for each cyanotoxin sample event.
Question: Preceding the finished water sample collection, did you observe any notable changes in source water quality parameters (if measured)?
YES = if yes, select all that apply to the source water:
  • ITP = Increase in water temperature
  • ITU = Increase in turbidity
  • IAL = Increase in alkalinity
  • ITO = Increase in total organic carbon
  • ICD = Increase in chlorine demand
  • IPH = Increase in pH
  • ICA = Increase in chlorophyll a
  • IPY = Increase in phycocyanin
  • INU = Increase in nutrients (example: nitrogen or phosphorus)
  • OTH = Describe other changes
NO = no changes observed

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