On December 18, 2014 the Ministry of the Environment and Climate Change sought stakeholder input on the “Technical Discussion Paper on Proposed Ontario Drinking Water Quality Standards” through EBR Registry # 012-1594.
The discussion paper proposed amendments to Ontario Regulation 169/03 (Ontario Drinking Water Quality Standards) made under the Safe Drinking Water Act, 2002 (SDWA) in order to adopt new drinking water standards for chlorate, chlorite, 2 methyl-4-chlorophenoxyacetic acid (MCPA), and haloacetic acids (HAAs), and to revise the existing standards for arsenic, benzene, carbon tetrachloride, and vinyl chloride.
The ministry is now seeking input on a more specific proposal to amend Ontario Regulation 169/03 and Ontario Regulation 170/03 (Drinking Water Systems) made under the SDWA, as well as any municipal licenses as appropriate in order to update the drinking water standards, and testing and reporting requirements. The proposed regulatory amendments incorporate stakeholder feedback, and fall into two groups:
- Amendments needed to implement the standards updates
a. Implementing the proposed standards as per the discussion paper
b. Updating the sampling and testing requirements
- Amendments being proposed to respond to stakeholder comments
a. Simplifying the reporting and resampling for trihalomethanes (THMs) and HAAs
b. Optimizing testing frequencies for smaller systems with a history of low levels of THMs and HAAs
c. Updating the chemical lists to remove legacy pesticides no longer in use, have been delisted, and have not been detected in drinking water samples for at least ten years
d. Providing phase-in periods for amendments to take effect
1a) Implementing Proposed Ontario Drinking Water Quality Standards
As described in the discussion paper, Schedule 2 to Ontario Regulation 169/03 is proposed for amendment as follows:
- Strengthen the standards for four substances already listed:
o arsenic (from 0.025mg/L to 0.010 mg/L);
o carbon tetrachloride (from 0.005mg/L to 0.002 mg/L);
o benzene (from 0.005mg/L to 0.001 mg/L);
o vinyl chloride (from 0.002 mg/L to 0.001 mg/L); and,
- Adopt standards for four substances not currently listed:
o chlorate (1 mg/L);
o chlorite (1 mg/L);
o 2-methyl-4-chlorophenoxyacetic acid [MCPA] (0.1 mg/L); and,
o haloacetic acids [HAAs] (0.080 mg/L as a running annual average of quarterly results).
1b) Updating the Sampling and Testing Requirements
With respect to the four substances for which standards would be strengthened (i.e. arsenic, carbon tetrachloride, benzene and vinyl chloride), the existing sampling and testing requirements in Ontario Regulation 170/03 would continue to apply.
With respect to the four substances for which standards would be newly adopted, the following sampling and testing requirements are proposed:
- Chlorate (new standard of 1.0 mg/L) testing would only be required for municipal drinking water systems using chlorine dioxide treatment equipment (currently 4systems in total). Testing requirements would be prescribed within the municipal licences for these systems, which would be updated as needed. Ontario Regulation 170/03 would not be amended to include testing requirements for chlorate;
- Chlorite (new standard of 1.0 mg/L) testing would also only be required for municipal drinking water systems using chlorine dioxide treatment equipment. As with chlorate, testing requirements for chlorite would be prescribed within the municipal licences for these systems and Ontario Regulation 170/03 would not be amended;
- MCPA (new standard of 0.1 mg/L) would be added to the list of organic chemicals that require testing a minimum of every 1 or 3 years (for large municipal residential systems, depending on source) or a minimum of every 5 years (for small municipal residential systems, non-municipal year-round residential systems, and systems serving designated facilities); and
- HAAs (new standard of 0.80 mg/L expressed as a running annual average of quarterly results) would need to be tested on a quarterly basis by municipal and non-municipal year-round residential systems providing chlorination or chloramination at a location in the distribution system that is likely to have an elevated potential for the formation of HAAs (similar to current requirements for THMs).
2a) Simplifying the Reporting and Resampling Requirements for THMs and HAAs
Proposed new provisions for adverse test reporting for THMs and HAAs would be based on results from each calendar quarter and the following specific practices:
- Within 7 days of the end of every calendar quarter, operating authorities / owners would be required to calculate a new running annual average and notify the existing authorities of any adverse test results - there would no longer be a requirement to make contact by telephone;
- Resampling would not be required as part of prescribed corrective actions because multiple test results are already being used in the calculation of the running annual average; and
- Laboratories that upload every individual THMs and HAAs test result into the ministry’s data system within 48 hours would no longer have to calculate and report running annual averages as adverse test results.
2b) Optimizing Testing Frequencies for Smaller Systems with a History of Low Levels of THMs and HAAs
Proposed amendments would allow small municipal and non-municipal year-round residential systems to carry out quarterly testing for THMs and HAAs every third year rather than every year once the system has demonstrated a 3-year history of having low levels of THMs or HAAs (all individual test results below half the standard).
- The changes to testing frequencies for HAAs would only apply once 3 consecutive years of results history for HAAs have been established in accordance with the regulations. Testing reductions for THMs may be available earlier because test histories for THMs have already have been established.
- The reductions would continue to apply if all individual results are maintained below half the standard, and if there are no significant changes to treatment equipment, water chemistry, or the raw water supply.
2c) Updating the Lists of Organic Chemicals to Remove ‘Legacy’ Pesticides No Longer in Use
In order to update the lists of organic chemicals used in drinking water regulations, it is proposed that thirteen (13) pesticides be removed. These thirteen chemicals are no longer in commercial use, have been withdrawn (de-listed) from the Canadian Drinking Water Quality Guidelines, and have not been detected in drinking water samples in Ontario for at least 10 years. The list of these pesticides is provided below:
- Aldrin + Dieldrin
- Chlordane (Total)
- Dichlorodiphenyltrichloroethane (DDT) + metabolites
- Heptachlor + Heptachlor Epoxide
- Lindane (Total)
- 2,4,5-Trichlorophenoxy acetic acid (2,4,5-T)
2d) Phase-In Periods for the Amendments to Take Effect
In order to allow system owners/operators a period to collect baseline information and provide for any necessary system upgrades, it is proposed that the amendments would be phased-in as follows:
- New sampling, testing, reporting, and resampling requirements and the removal of 13 pesticides – would come into effect as of January 1, 2016;
- New testing requirements for HAAs and THMs testing optimization rule for smaller systems– would come into effect as of January 1, 2017;
- Updates to standards for carbon tetrachloride, benzene, vinyl chloride, chlorate, chlorite, and MCPA – would come into effect / require reporting as of January 1, 2017;
- Update to standard for arsenic – would come into effect / require reporting as of January 1, 2018; and
- New standard for HAAs and HAAs testing optimization rule for smaller systems – would come into effect / require reporting as of January 1, 2020.