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1. What is your name?
Name
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Peter Dysart Trolove
Section 2: Proposal 1 - How at-risk source water areas are delineated
1. Domestic and international evidence suggests that delineating three at-risk areas is a good approach for protecting sources of drinking water. Do you think this is a good approach for protecting our source waters?
Please select one item
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Yes
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No
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Unsure
Please explain your response here
While delineating three at risks areas seems fair enough, a national set of standards is not appropriate.
I have been monitoring monthly nitrate levels in the largely aquifer fed surface waters, and a number of bores, in the Selwyn District of Canterbury since August 2019.
It is very clear that the models used by Ecan, (the Canterbury Regional Council), are too coarse grained and simplistic to reflect the movement of water through the semi-confined aquifer layers and overlying soils that have formed from the outwash gravel fans that formed the central Canterbury Plains.
The variation in my results indicate water transport times for groundwater vary widely due to underground "streams".
The naturally intermittent Selwyn River is greatly influenced by the periods when it is connected to its inland permanently flowing sections. At these time the nitrate levels drop only to return to unacceptable levels as the middle sections lose their surface flows to groundwater. The groundwater flows have been estimated to take as little as two to 14 days to pass beneath the central Canterbury Plains making a nonsense of the 2.5 km / year default.
Bores with high nitrate contamination appear to be linked to preferential underground "streams" contaminated many kilometers upslope by factory or sewage wastewater applied to farmland.
In summary a "one size fits all will not provide adequate protection in the Selwyn District. This is likely to be the case to a greater or lesser degree along the East Coast of the South Island where similar geology exits.
Conversely water logged anoxic soils such as around Greenpark have quite low nitrate levels due to denitrification and probably much slower water movement through soils.
I have been monitoring monthly nitrate levels in the largely aquifer fed surface waters, and a number of bores, in the Selwyn District of Canterbury since August 2019.
It is very clear that the models used by Ecan, (the Canterbury Regional Council), are too coarse grained and simplistic to reflect the movement of water through the semi-confined aquifer layers and overlying soils that have formed from the outwash gravel fans that formed the central Canterbury Plains.
The variation in my results indicate water transport times for groundwater vary widely due to underground "streams".
The naturally intermittent Selwyn River is greatly influenced by the periods when it is connected to its inland permanently flowing sections. At these time the nitrate levels drop only to return to unacceptable levels as the middle sections lose their surface flows to groundwater. The groundwater flows have been estimated to take as little as two to 14 days to pass beneath the central Canterbury Plains making a nonsense of the 2.5 km / year default.
Bores with high nitrate contamination appear to be linked to preferential underground "streams" contaminated many kilometers upslope by factory or sewage wastewater applied to farmland.
In summary a "one size fits all will not provide adequate protection in the Selwyn District. This is likely to be the case to a greater or lesser degree along the East Coast of the South Island where similar geology exits.
Conversely water logged anoxic soils such as around Greenpark have quite low nitrate levels due to denitrification and probably much slower water movement through soils.
2. In your view, is the method to determine each SWRMA, for each type of water body, the best option?
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Yes
Radio button:
Unticked
No
Radio button:
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Unsure
Please explain your response here
Very broadly yes, (river, lake, bore).
However in Canterbury the connections between rivers and groundwater can be rapid and certainly variable.
The Rakaia River for example loses up to 40 cubic meters/second to groundwater between the gorge and the coast.
When this river is experiencing major floods the hydraulic connection is evidenced by the drains from the Rakaia river mouth as far as Cooper's lagoon about 7 km away rising and falling in parallel with the river flows.
Understanding local geology is paramount. Bespoke SWRMAs are needed for vulnerable porous Canterbury soils. Less reliance on models and greater monitoring is required
However in Canterbury the connections between rivers and groundwater can be rapid and certainly variable.
The Rakaia River for example loses up to 40 cubic meters/second to groundwater between the gorge and the coast.
When this river is experiencing major floods the hydraulic connection is evidenced by the drains from the Rakaia river mouth as far as Cooper's lagoon about 7 km away rising and falling in parallel with the river flows.
Understanding local geology is paramount. Bespoke SWRMAs are needed for vulnerable porous Canterbury soils. Less reliance on models and greater monitoring is required
3. For lakes, do you agree that SWRMA 2 should include the entire lake area?
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Yes
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No
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Unsure
4. SWRMA 1 for lakes and rivers is proposed to extend 5 metres into land from the river/lake edge. This contrasts with 3 metre setback requirement of the Resource Management (Stock Exclusion) Regulations 2020. SWRMA 1 is proposed to be used as a basis for controlling activities close to source water intakes, and applies to a wide range of activities. Do you think these differing setbacks will cause confusion or result in other challenges?
Please select one item
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Ticked
Yes
Radio button:
Unticked
No
Radio button:
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Unsure
Please explain your response here
The three meter setback is a political compromise
Even 5 meters might only help reduce 90% or the sediment load entering waterways.
Practically any fixed setback fails due to variable river and stream flows.
In lowland Canterbury it is common to see low lying paddocks with pools of water from recent rains surrounding and connected to fenced streams.
Moveable temporary fencing may be a better option
Even 5 meters might only help reduce 90% or the sediment load entering waterways.
Practically any fixed setback fails due to variable river and stream flows.
In lowland Canterbury it is common to see low lying paddocks with pools of water from recent rains surrounding and connected to fenced streams.
Moveable temporary fencing may be a better option
5. There is evidence suggesting that a 10–30-metre radius around source water bores is a preferable way to delineate the area where activities would be heavily restricted (SWRMA 1). However, expert advice suggests a 5-metre radius is the most workable option. Do you agree that a 5-metre radius around a source water bore gives enough protection?
Please select one item
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Unticked
Yes
Radio button:
Ticked
No
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Unsure
Why or why not? If not, what alternative would you suggest?
I spent some time working as a meat vet.
At one premises the plant found its bores contaminated from its septic tanks due to increased usage as the plant expanded.
The distance between the septic tanks and contaminated bores was nearer 20 t0 30 meters.
(Porous Canterbury soils!)
At one premises the plant found its bores contaminated from its septic tanks due to increased usage as the plant expanded.
The distance between the septic tanks and contaminated bores was nearer 20 t0 30 meters.
(Porous Canterbury soils!)
6. While water takes from complex spring systems or wetlands may require a bespoke SWRMA to ensure consideration of any contamination pathways present, a default method is necessary to ensure interim protection. Do you think a default method is practicable in most situations?
Please select one item
Radio button:
Unticked
Yes
Radio button:
Ticked
No
Radio button:
Unticked
Unsure
Please explain your response here
Case by case.
Experience as a meat vet where oversight of a premises' potable water was part of my job description.
A default method would have failed on several occasions
Experience as a meat vet where oversight of a premises' potable water was part of my job description.
A default method would have failed on several occasions
7. How long do you think is necessary for regional councils to delineate SWRMAs for currently registered water supplies in each region using the default method?
Please explain your response here
ASAP
Public Health standards for potable water for EU & USDA/FDA are non negotiable.
Food Safety standards for New Zealanders are of a lower standard and at times even politically determined, (e.g. when a supplier seeks assistance from his local MP).
Public Health SHOULD take priority over commercial considerations of Agribusiness interests.
Public Health standards for potable water for EU & USDA/FDA are non negotiable.
Food Safety standards for New Zealanders are of a lower standard and at times even politically determined, (e.g. when a supplier seeks assistance from his local MP).
Public Health SHOULD take priority over commercial considerations of Agribusiness interests.
8. What challenges do you foresee in delineating SWRMAs, when previously unregistered supplies are registered with Taumata Arowai (see Proposal 3 for more details)?
Please explain your response here
Cost
Demonstrating the SWRMAs are scientifically defensible
Scale
Demonstrating the SWRMAs are scientifically defensible
Scale
9. What support could enable regional councils to delineate SWRMAs within shorter timeframes?
Please explain your response here
Trustworthy science
Trustworthy councils
Both are absent in Canterbury
A culture change including a long overdue shake up at Ecan both councilors and staff
Trustworthy councils
Both are absent in Canterbury
A culture change including a long overdue shake up at Ecan both councilors and staff
10. Do you think consideration should be given to mapping currently unregistered supplies as they register (but before the four-year deadline provided under the Water Services Act), or do you think that waiting and mapping them all at the same time is a better approach?
Please explain your response here
Spread the work load
11. If a regional council has already established local/regional source water protection zones through a consultative process, should there be provision to retain that existing protection zone as a bespoke method without further consultation or consideration against new national direction?
Please explain your response here
I am in favor of bespoke methods that are validated by routine monitoring.
I am not a fan of the "consultative process" as set out by the Canterbury Water Management Strategy where water users and polluters set the freshwater standards for Canterbury's 10 water zones.
Groundwater pollution with pathogens and nitrate in Canterbury is measurably increasing - evidence that Ecan's Farm Environment Plans are inadequate.
[Morgan & Dench 2018]
I am not a fan of the "consultative process" as set out by the Canterbury Water Management Strategy where water users and polluters set the freshwater standards for Canterbury's 10 water zones.
Groundwater pollution with pathogens and nitrate in Canterbury is measurably increasing - evidence that Ecan's Farm Environment Plans are inadequate.
[Morgan & Dench 2018]