LGOIMA Request Details: LG2024
Date received: 13/09/2021
Requested information: Investigation of nitrate contamination of New Zealand drinking water
Status: Complete
Date responded: 08/10/2021
Response:
Specifically, to make the most comprehensive dataset possible, we are requesting:
1) The Comprehensive Chemical Analysis Reports (lab reports)
Lab reports for each Water Supply Zone with appropriate supply zone code (eg, "CHR001CE") back as far as records are held (eg, year 2000). For supply zones with multiple sources, could you provide some guidance on the best assumptions to apply to estimate the most accurate measurement for the median level each year for that supply zone. We are requesting data on all determinands that have been tested for in that year.
Provision of lab reports would ensure consistency of the data between suppliers, address any data entry errors and allow us to control for any confounding contaminants (eg, disinfection by-products). If this data is not available within council records, our initial discussions with one large testing lab suggest we could retrieve the achieved data upon permission from the supplier. We would be happy to cover any costs of this data extraction process with the labs.
Preferable format: Lab report produced by the testing lab (PDF) that is currently held by the council.
Alternative format: Written and explicit permission to access achieved lab records for all water supply zones under your jurisdiction.
Please find attached lab results from one of our lab providers. Eurofins covering the period 2007 to 2021. There are lab results for two supplies at Longburn and Bunnrythrope which are now operated by Palmerston North City Council since a boundary change in 2014.
We have also contacted our other lab provider Central Environmental Labs to give them permission to release any data they have for our supplies to you.
2) Longitudinal Chemical Analysis Data
We are seeking water quality data as far back as records provide. If more than one test was conducted per year, we would want multiple records for each year. We would use the yearly median value in any future exposure assessment.
Preferable format: Same as above
Alternative format: Same as above
Same answer as request 1
3) Spatial Data on Water Supply Zones
Any geographic data on the Water Supply Zones, preferably with some indication (variable) of the appropriate Water Supply Zone code (eg, "CHR001CE"). If multiple versions of these supply zones exist over time we would like all versions you have on record so we can compare changes within zones over time. This will enable us to account for changes in supply zones and creation of new residential developments.
Preferable format: Shapefile [file type], New Zealand Transverse Mercator (NZTM2000) [projection], Polygon [feature type], supply zone code [variable]
Alternative format: Whatever is available
Spatial Data for our Water Supplies is as supplied to the Drinking Water Online Database which you have access to. I have checked the files e-mailed to me on 24 September 2021 and these represent the current water scheme boundaries. Mt Taylor is part of the Feilding Water Supply Scheme. Bunnythorpe and Longburn Water Supply Schemes are no longer operated by Manawatu District Council but we have included some data for these supplies prior to 2014.
4) Any additional information on private supplies
Any information you may hold on water quality of private supplies in your area. Ideally, these would include the address of the sample but could be aggregated to a higher spatial level [eg suburb, city or postcode]– please do not provide any names or contact information of the private supplies.
We have provided the spatial area for the private supplies at Kiwitea No. 1 an Oroua No. 1.
We have no water testing results for these supplies