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Sludge Surveys

Sludge Surveys in New Zealand

The purpose of a sludge survey is to verify the amount and characteristics of sludge present in a wastewater pond. A sludge survey also determines the condition of the sludge and to identify any potential issues that may affect the treatment process or the environment. A sludge survey is a prudent first step for operators looking to understand the condition and capacity of their wastewater pond and with a view to potentially removing the sludge from the pond.



During a sludge survey, various parameters may be measured and analyzed, such as the volume of sludge, the percentage of solids, the moisture content, the pH level, and the presence of heavy metals and or pathogens.

The information gathered during a sludge survey can be used to make decisions about the best options for sludge removal, treatment, and disposal. For example, if the sludge survey indicates that the sludge is contaminated with high levels of pollutants, it may be necessary to treat the sludge before it is disposed of to prevent environmental contamination.

Overall, a sludge survey is an important tool for wastewater treatment plant operators and environmental regulators to ensure that sludge is managed in the most safe and environmentally responsible manner.


To undertake a sludge survey, SiteCare will attend your wastewater pond with our specialised equipment, which includes a low draught small boat fitted with specialised instruments and GPS equipment. The wastewater pond will be traversed in a grid formation, with the instruments taking readings at each waypoint on the grid.

We will also collect sludge samples from your wastewater pond, these will be delivered to a laboratory for testing. These test results will determine the density of the sludge, but also any contaminants.

Ponds that have received industrial waste in the past are more likely to have contaminants such as heavy metals in the sludge that may be harmful to the environment. The level and type of contaminants can significantly influence the repurposing possibilities for the sludge once it has been dredged from the pond and dewatered.

Why Trust SiteCare for Your Sludge Surveys?

SiteCare have been delivering professional sludge surveys throughout New Zealand for over 5 years.

Once we have gathered all of the information about the sludge in your wastewater pond we will provide you with a comprehensive and detailed sludge survey report. The critical information in this report and specifically the Total Dry Solids (tDS) volume of sludge in your wastewater pond will allow you to make informed decisions on sludge removal and budgeting for your pond maintenance.


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