Growth, Housing and Environment
Report
Water (Jersey) Law 1972 – Duty to Monitor Water
Purpose of the Report
The Minister for the Environment (The Minister) is requested to:
Approve the Monitoring Programme submitted by The Jersey New Waterworks Company Limited (Jersey Water) for the calendar year 2019.
Background
Under Article 10(4) of the Water (Jersey) Law 1972 as amended, The Jersey New Waterworks Company Limited (Jersey Water) is required to submit its monitoring programme each year to the Minister for his or her approval.
The programme submitted for 2019 is attached to this report. It has been reviewed by the department and is deemed fit for purpose.
The Monitoring Programme is based on best practice.
Recommendation
The Minister is recommended to approve the monitoring programme.
Written by: Director – Environmental Health
Approved by: Group Director – Regulation, Growth, Housing and Environment
20th December 2018
Ministerial Decision Case: MD-PE-2019-0002
Proposed Regulatory Monitoring Schedule For The Year 2019
It is proposed that Jersey Water use the following risk assessment based monitoring programme for 2019.
Water Supply Zone
Table 1 sets out the frequency of sampling for check monitoring of parameters in the water supply zone.
Table 1
Check monitoring |
Parameter | Proposed Sampling Frequency |
E.coli | 12 per 5,000 population ie 240 |
Coliform bacteria |
Residual disinfectant |
Aluminium | 76 |
Ammonium | 76 |
Clostridium Perfringens | 76 |
Colony counts | 76 |
Colour | 76 |
Conductivity | 76 |
Cyanide | 76 |
Hydrogen ion | 76 |
Iron | 76 |
Manganese | 76 |
Nitrate | 76 |
Nitrite | 76 |
Odour | 76 |
Taste | 76 |
Turbidity | 76 |
The Company uses aluminium sulphate as a flocculant in the primary treatment process, therefore the sample frequency for aluminium will be at the check monitoring frequency.
As the water the Company uses originates from, or is influenced by, surface waters, the sampling frequency for iron and manganese will be at the check monitoring frequency.
The Company uses chloramination as one of its disinfection processes; therefore the sampling frequency for nitrite will be at the check monitoring frequency.
- There are no proposed changes to check monitoring in the water supply zone in 2019 compared to 2018.
Table 2 sets out the frequency of sampling for audit monitoring of parameters in the water supply zone.
Table 2
Audit monitoring |
Parameter | Proposed Sampling Frequency |
Antimony1 | 1 |
Arsenic2 | 1 |
Benzene3 | 1 |
Benzo(a)pyrene4 | 0 |
Boron | 8 |
Cadmium5 | 1 |
Chromium5 | 1 |
Copper | 8 |
1,2 dichloroethane6 | 1 |
Enterococci | 8 |
Fluoride | 8 |
Lead | 8 |
Mercury7 | 0 |
Nickel | 8 |
Polycyclic aromatic hydrocarbons4 | 0 |
Selenium8 | 1 |
Sodium9 | 1 |
Trichloroethene }6 Tetrachloroethene } | 1 |
Tetrachloromethane6 | 1 |
Trihalomethanes | 8 |
Chloride10 | 1 |
Sulfate10 | 1 |
Total organic carbon | 8 |
Gross alpha11 | 4 |
Gross beta11 | 4 |
Proposed changes to audit monitoring in the water supply zone in 2019 compared to 2018 are as follows:
- All parameters are assessed to ensure that risks are covered at the appropriate frequency in the monitoring schedule. The audit parameters were assessed at the full audit frequency in 2018 (8 per annum), to revisit the risk assessment undertaken in 2012 for the 2013 schedule, plus to inform the 2019 schedule. A number of frequencies have been reduced or stopped, in line with DWI best practice of reducing sample frequency with consistent results below 60% and cessation below 30% of the parametric value.
- Antimony. Mostly an issue for some distribution alloys. No historical issue and to date all the results for 2018 are less than 5% of the prescribed concentration and therefore audit monitoring for antimony is to be reduced.
- Arsenic. Primarily a ground water contaminant, no historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for arsenic is to be reduced.
- Benzene. Principally resulting from hydrocarbon pollution, no historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for benzene is to be reduced.
- Benzo(a)pyrene and Polycyclic Aromatic Hydrocarbons (PAH’s). Both are linked to coal tar lined water mains, none are known about in the Island. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for benzo(a)pyrene and polycyclic aromatic hydrocarbons will cease to be undertaken.
- Cadmium and Chromium. Both may occur naturally at very low levels, but higher amounts could be associated with industrial pollution. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for cadmium and chromium are to be reduced.
- 1,2 dichloroethane, Trichloroethene, Tetrachloroethene and Tetrachloromethane. These are industrial chemicals that are only an issue in some groundwater’s. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for 1,2 dichloroethane, trichloroethene, tetrachloroethene and tetrachloromethane is to be reduced.
- Mercury. May occur naturally at very low levels, but higher amounts could be associated with industrial pollution. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for mercury will cease to be undertaken.
- Selenium. May occur naturally at very low levels, but higher amounts could be associated with industrial pollution. No historical issue and to date all the results for 2018 are less than 20% of the prescribed concentration and therefore audit monitoring for selenium is to be reduced.
- Sodium. Only a problem with regard to taste at very high concentrations but the nature of the Island means it will be found in surface water (windblown sea spray). However, there has been no historical issue and to date all the results for 2018 are less than 35% of the prescribed concentration and therefore audit monitoring for sodium is to be reduced.
- Chloride and sulfate. Only a problem with regard to taste at high concentrations, there has been no historical issue and to date all the results for 2018 are less than 35% of the prescribed concentration and therefore audit monitoring for chloride and sulfate is to be reduced.
- Radioactivity. These parameters are measured as part of initial screening for radioactivity in drinking water. Jersey Water sources have been assessed as very low risk and therefore audit monitoring for radioactivity is to be reduced.
- Pesticides. As in 2018, during 2019 monitoring for pesticides will be undertaken at the treatment works and not in the supply zone. This will allow for more concentrated monitoring to be undertaken and also allow for more substances to be monitored on a more frequent basis. If any breaches are recorded monitoring of the affected supply zone will be undertaken.
Treatment Works
The Company has two water treatment works located at Augres WTW and Handois WTW. Both treatment works use clarifiers (chemical assisted sedimentation) for primary treatment, followed by rapid gravity filtration using dual media (anthracite and sand). During 2017 Augres WTW supplied an average of 10,238 m3/d and Handois WTW 9,836 m3/d.
Table 3 sets out the frequency of sampling for both check and audit monitoring of parameters at the treatment works.
Table 3
Substances and parameters | Proposed Sampling Frequency |
E.coli | 208 |
Coliform bacteria | 208 |
Colony counts | 208 |
Nitrite | 104 |
Residual disinfectant | 208 |
Turbidity | 208 |
Clostridium Perfringens | 52 |
Conductivity | 52 |
Cyanide | 52 |
Subject to audit monitoring |
Benzene1 | 1 |
Boron | 8 |
Bromate | 8 |
1,2 dichloroethane2 | 1 |
Fluoride | 8 |
Mercury3 | 0 |
Pesticides and related products | 52* |
Trichloroethene }2 Tetrachloroethene } | 1 |
Tetrachloromethane2 | 1 |
Chloride4 | 1 |
Sulphate4 | 1 |
Total organic carbon | 8 |
Gross alpha5 | 4 |
Gross beta5 | 4 |
* Frequency for pesticide analysis will be based on the individual substances risk-assessed threat to the water supply, up to a maximum of 52 analyses in the year. The proposed pesticide analysis will be forwarded once the risk assessment has been completed.
The Company uses chloramination as one of its disinfection processes; therefore the sampling frequency for nitrite will be at the check monitoring frequency.
The Company does not add sodium hypochlorite after the water has left the treatment works, therefore audit monitoring for bromate (a possible disinfection by-product) shall take place at the treatment works.
Check monitoring of nitrite at the treatment works will continue at the reduced rate - results for the last two years have been well below the EU regulatory limit of 0.1 mg/l, the highest result being 0.016 mg/l.
Proposed changes to audit monitoring at the treatment works in 2019 compared to 2018 are as follows:
- All parameters are assessed to ensure that risks are covered at the appropriate frequency in the monitoring schedule. The audit parameters at the treatment works were assessed at the full audit frequency in 2018 (8 per annum), to revisit the risk assessment undertaken in 2012 for the 2013 schedule, plus to inform the 2019 schedule. A number of frequencies have been reduced or stopped, in line with DWI best practice of reducing sample frequency with consistent results below 60% and cessation below 30% of the parametric value.
- Benzene. Principally resulting from hydrocarbon pollution, no historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for benzene is to be reduced.
- 1,2 dichloroethane, Trichloroethene, Tetrachloroethene and Tetrachloromethane. These are industrial chemicals that are only an issue in some groundwater’s. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for 1,2 dichloroethane, trichloroethene, tetrachloroethene and tetrachloromethane is to be reduced.
- Mercury. May occur naturally at very low levels, but higher amounts could be associated with industrial pollution. No historical issue and to date all the results for 2018 are less than the limit of detection and therefore audit monitoring for mercury will cease to be undertaken.
- Chloride and sulfate. Only a problem with regard to taste at high concentrations, there has been no historical issue and to date all the results for 2018 are less than 35% of the prescribed concentration and therefore audit monitoring for chloride and sulfate is to be reduced.
- Radioactivity. These parameters are measured as part of initial screening for radioactivity in drinking water. Jersey Water sources have been assessed as very low risk and therefore audit monitoring for radioactivity is to be reduced.
Service Reservoirs
The Company has treated water service reservoirs (SR) at Westmount Road, St. Helier (9Ml capacity) and Les Platons, Trinity (9Ml capacity).
Table 4 sets out the frequency of sampling for check monitoring of parameters at the service reservoirs.
Table 4
Substances and parameters | Proposed Sampling Frequency |
E.coli | 52 |
Coliform bacteria | 52 |
Colony counts | 52 |
Residual disinfectant | 52 |
It is proposed that analysis for the parameters given in the monitoring schedules will be undertaken by either the Company laboratory or their consulting analysts.
29th June 2018