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Contaminants such as heavy metals (zinc, copper and lead) and synthetic organics (oil and other petrochemical derivatives) can be measured in industrial stormwater runoff throughout Auckland. IWS Group have long been concerned about the potential mixture of chemicals that can be present in poorly managed industrial site stormwater runoff and the potential effects that they can cause on the receiving waterways.

To mitigate against stormwater discharges from higher-risk industrial sites, Industrial Trade Activity (ITA) consents are required with Local Council to promote regular monitoring of water quality to ensure compliance with the consent requirements. Our clients use this information for loss monitoring to isolate certain areas of their industrial site, find the problems in a treatment system and identify maintenance requirements of filters.


Rather than addressing the water quality related issue at the catchment, we believe in a preventative approach 'upstream' to limit contaminants entering the system in the first place. We do this through effective monitoring and data collection.


One of the most difficult to quantify and manage is the cumulative effect that arises from minor and seemingly insignificant discharges that routinely occur as a part of industrial site activities. The initial runoff that occurs from hard surfaces when it rains, termed the ‘first flush’ is often found to be the most heavily contaminated as later runoff has lower levels of contaminants to be washed off and there is greater volume for dilution. Click here for further information on stormwater. 


Our Professional Service to You

In order to meet ITA consents requirements, we provide composite water sample collection, pH logging and analysis equipment to monitor various parameters.This provides us with unparalleled insight into detailed trends and historic patterns of stormwater during a rainfall event. Interpretation and reporting on compliance of the resulting data with the specified standard can then be conducted. A wide range of analytes can be arranged with results being available on an urgent basis if required. These include: 

  • Heavy metals (Aluminium, Copper, Iron, Lead, Zinc)20160209 130300
  • Total Suspended Solids
  • Oil & Grease
  • pH
  • Sulphate
  • Electroconductivity
  • COD (Chemical Oxygen Demand)
  • BOD (Biochemical Oxygen Demand)
  • Nutrients (Phosphorus, Nitrogen)
  • Organic Compounds (Pesticides

Trade Waste

Sanitarium web

Wastewater discharges from industrial and commercial sites may contain contaminants at concentrations that can affect the quality of receiving waters or interfere with publicly owned treatment systems that receive those discharges. To mitigate against this, Trade Waste Agreements (TWA's) have been introduced in conjunction with the Auckland Trade Waste Bylaw 2013, the region-wide standard for the management, regulation and risk classification of trade waste.

IWS can interpret the resulting data and report on compliance with the specified standard. IWS has a range of sampling, logging and analysis equipment, which can be used to monitor various parameters. Examples are pH, temperature, conductivity and flow logging and composite sample collection. A wide range of chemical and biological analyses can be arranged for the client, with results being available on an urgent basis if required.


pH Probe Servicing and Calibration

Trade waste pH monitoring ensures waste water discharges to the network are not excessively too acidic or alkaline. Prolonged high or low pH can deteriorate publicly-owned underground infrastructure including pumps, concrete pump chambers and pipe linings. pH compliance is therefore an important parameter to meet, and often requires advanced understanding of pH equipment to ensure accuracy and consistent data. Being specialists at installing pH correction equipment, we offer regular calibration and maintenance of equipment such as pH probes and controls.