Waikato Regional Council will, in conjunction with organisations, industry groups and individuals, provide guidance on good practice techniques for the reuse of biosolids and nonhazardous byproducts from industrial and trade premises as soil conditioners or fertiliser substitutes.
The discharge of sludges and liquids from activated sludge treatment processes onto or into land outside the Lake Taupo Catchment and any consequent discharge of contaminants to air is a permitted activity subject to the following conditions:
The discharge of biosolids or sludges and liquids from activated sludge treatment processes onto or into land outside the Lake Taupo Catchment, and any subsequent discharge to air, that is not permitted by Rule 126.96.36.199 is a controlled activity (requiring resource consent) subject to the following standards and terms:
Waikato Regional Council reserves control over the following matters:
The discharge of biosolids into water or onto or into land that does not comply with Rules 188.8.131.52 and 184.108.40.206 is a discretionary activity (requiring resource consent).
Exclusion to Rule 220.127.116.11:
Discharges of contaminants (not including stormwater or contaminants associated with the take and use of geothermal water), into Natural State Water Bodies, natural wetlands (that are habitat for indigenous vegetation or fauna communities), cave entrances or lakes (excluding artificial lakes and Lake Rotoaira) are excluded from this rule. The effects of these activities are managed by Rule 18.104.22.168 of this Plan.
Exclusion to Rule 22.214.171.124:
Discharges of contaminants within 20 metres of Significant Geothermal Features are excluded from this Rule. The effects of these activities are managed by Rule 126.96.36.199 to 188.8.131.52 of this Plan.
|Enteric Viruses||<1 PFU/4g|
|Arsenic||20 mg/kg dry weight|
|Cadmium||1 mg/kg dry weight|
|Chromium||600 mg/kg dry weight|
|Copper||100 mg/kg dry weight|
|Lead||300 mg/kg dry weight|
|Mercury||1 mg/kg dry weight|
|Nickel||60 mg/kg dry weight|
|Zinc||300 mg/kg dry weight|
|DDT/DDD/DDE||0.5 mg/kg dry weight|
|Aldrin||0.02 mg/kg dry weight|
|Dieldrin||0.02 mg/kg dry weight|
|Chlordane||0.02 mg/kg dry weight|
|Heptachlor and Heptachlor epoxide||0.02 mg/kg dry weight|
|Hexachlorobenzene (HCB)||0.02 mg/kg dry weight|
|Hexachlorocyclohexane (Lindane)||0.02 mg/kg dry weight|
|Benzene Hexachloride (BHC)||0.02 mg/kg dry weight|
|Total polychlorinated biphenyls||0.02 mg/kg dry weight|
|Total dioxin TEQ||0.00003 mg/kg dry weight|
Explanation and Principal Reasons for Adopting Methods 184.108.40.206 to 220.127.116.11
Method 18.104.22.168 identifies that guidelines defining good practice techniques are a valuable tool in managing the effects of these discharges. Waikato Regional Council will provide guidance on the development of these guidelines. In particular, good practice guides need to focus on means of applying these wastes to land so that neither soils nor ground water are contaminated as a consequence of over-application or application during the wrong season.
The rule framework in Rules 22.214.171.124 to 126.96.36.199 recognises that biosolids and other nonhazardous byproducts from industrial or trade premises can be suitable for use as soil conditioners and fertiliser substitutes in accordance with Policies 1, 2 and 4. However, because of their source, these substances may contain hazardous contaminants to levels that will contaminate soil or water. Due to their source and typical composition, these substances may also generate objectionable levels of odour. Because of these risks, some control must be exercised to ensure that the substance will not contaminate soils, generate odours or result in contamination of surface and ground water.
Only discharges of biosolids, sludges and liquids from activated sludge treatment processes are permitted by these Rules. The treatment process that they have been subject to means that the objectionable odours associated with anaerobic processes are largely removed. For example, material can be processed through a clarifier and aerated, resulting in an activated sludge. Provided they are applied in the same way as other fertilisers such as farm animal effluent, the risk of adverse effects is minimal.
Rule 188.8.131.52 provides for the beneficial reuse of biosolids sourced from municipal wastewater treatment plants and industrial sources provided that contaminants within the biosolid are sufficiently low that there is little risk of creating a new contaminated site through continual application of the material. The contaminant levels in Table 3-8 are derived from the Guidelines for the Safe Application of Biosolids in New Zealand (NZWWA, 2003). To ensure that the objectives and policies in Chapter 5.2 of the Plan are achieved, the levels are set at the contaminant levels deemed by that guideline to be acceptable from 2012 rather than the less conservative values recommended from 2003 - 2012. With this exception, biosolids or other effluents that have obtained registered Biosolids Quality Mark accreditation or equivalent are enabled by this Rule.
As biosolids can be high in nutrients, it is not appropriate to allow their discharge within the Taupo catchment as a Permitted or Controlled Activity. For this reason, the discharge of biosolids to land in the Taupo catchment is a Discretionary Activity under rule 184.108.40.206. Such discharges may also be assessed in accordance with the Taupo land use rules 220.127.116.11 to 18.104.22.168 if they result from farming activities.