Water Testing with ARL​

Our range of water, waste water, irrigation and effluent testing services are designed to assist the agricultural, horticultural and food industries by helping our clients meet regulatory and environmental monitoring requirements and to identify potential problems and solve existing ones.

The following testing suites have been put together to meet the needs of the most common test enquiries that we receive, however there is a full range of extra tests that can be selected to meet any additional requirements you may have.

Getting the measure of your water quality 

Domestic and drinking water suite

Drinking poor quality water can be the cause of illness.

An effective water sampling programme can prevent this, as chemical contaminants of drinking water often cause adverse health effects after prolonged periods of exposure. Reticulated water supplies from City and District Councils provide surety to the property gate through regular testing programmes but not at the kitchen tap.

ARL’s domestic and drinking water suite is suitable for analysing the quality of water from reticulated water supplies, wells, bores, streams, springs, reservoirs and collected rain water.

Why sample for domestic and drinking water?

  • Benchmarks your results against current NZ Drinking Water Standards.
  • Ensures drinking water safety for health.
  • Identifies water quality issues and offers advice on reticulation and treatment options.
  • Identifies hardness of the water (hard water contains high levels of dissolved minerals).

Irrigation suite

The quality of irrigation water can have a profound influence on crop production, maturity and quality. To maximise your investment in plant and property, irrigation water quality should be evaluated before using a new water supply or purchasing a property.

Eurogap protocols recommend that irrigation water should be tested annually.

Why sample for irrigation?

  • Benchmark against irrigation critical values to optimise crop production.
  • Assess potential toxicity problems with elements such as chloride and boron.
  • Assess irrigation water quality for long term effects such as changes in soil pH and soil degradation through excessive sodium.
  • Determine potential for plant injury from highly saline (dissolved salts) in irrigation water.
  • Identifies water quality issues and offers advice on reticulation and treatment options.

Water softener suite

Hard water is water that contains high levels of dissolved minerals. The most common hardness causing minerals are calcium and magnesium. Consequences of hard water include the formation of a hardness scale in the hot water heater (and other appliances), soap scum and unwanted taste in cooked foods. The hardness scale in hot water heaters can build up, blocking plumbing, leading to increased electric or gas bills and the early failure of the appliance.

Why sample for water softener?

  • Identifies the efficacy and effectiveness of your current water softener system.

Farm dairy effluent (FDE) suite

FDE applied in the correct manner can save on the fertiliser bill to the tune of $290/ha/year. The nutrient value of effluent varies greatly from farm to farm and even with a farm over the season. Therefore sampling in Spring, Summer and Autumn, in conjuction with Overseer nutrient budget modelling is recommended to estimate long term nutrients applied to effluent block.

Why sample for farm dairy effluent?

  • Provides an insight into the fertiliser value of your effluent.
  • Assists in the correct calculation of land area and application rate. Inadequate land area can increase nitrate leaching, ponding of effluent, elevated pasture potassium which can induce metabolic complications in stock, and decrease the sustainability of the operation.
  • In conjunction with Overseer nutrient budget modelling ensures land application of effluent is within maximum application rates (150-200 kg N/ha/yr) as recommended by Regional Councils. You should confirm the local maximum rates with your local authority.
  • FDE application adds organic matter to the soil and increases earthworm activity.

Which FDE analysis?

ARL offers two main analytical suites for FDE:

  • Where FDE is applied back onto the land the “Farm Dairy Effluent Suite” is recommended.
  • Where FDE is treated through a two stage pond system and discharged into a receiving waterway, the “Discharge into Receiving Waterways Suite” is recommended.

Sampling of FDE being applied to the land

  • The nutrient value of effluent varies greatly from farm to farm and even within a farm over the season. Mineral content of FDE is likely to peak during September to October. Collecting a sample for nutrient analysis at this stage provides the optimum time to sample FDE if only sampling once a year (higher frequency of sampling is recommended).
  • Samples of FDE can be taken from storage ponds, dairy sumps or from the spray irrigator head. If possible sampling from the spray irrigator over a milking or period of time is recommended to obtain best representation of what is being applied.

Environmental impact suite

Nutrient enrichment (eutrophication) is due to the response in water to over-enrichment by nutrients from natural and "man-made" sources. This over-enrichment leads to the growth of rooted aquatic plants at the exclusion of other plants, algal mats, and deoxygenation which in turn can lead to stress of aquatic life. The main nutrients implicated in eutrophication are phosphorus and nitrogen. Nutrient sources that can contribute to eutrophication include municipal, industrial wastewater, agricultural runoffs, and urban runoffs.

Why sample for environmental impact?

  • To monitor the environmental impacts over time on the surrounding waterways of the operation. This testing suite monitors the main nutrients implicated in nutrient enrichment of water systems to within low levels of detection to effectively monitor any changes in nutrient levels over time.

Salinity suite

Salinity is the measure of the total amount of salt in water and is measured by the conductivity of the water. Both sodium and chloride can cause potential for plant injury if in high enough concentrations in irrigation water.

Excess salinity in irrigation water can also cause excessive soil sodium levels which will lead to deterioration in soil structure.

Exploratory water wells should also be analysed for salinity to determine if water is fit to drink.

Why sample for salinity?

  • To assess potential for plant injury from salinity in irrigation water without incurring the full expense of selecting the “Irrigation Suite”.
  • To assess risk of raising sodium loadings in the soil to levels where soil structure will deteriorate.
  • To assess whether water is fit to drink (The “Domestic and Drinking Water Suite” is recommended for drinking water).

How to take water samples

Please refer to our water testing sampling guide (below) for full details of how to take water samples.

Water testing documentation

Water testing price list
Water testing sampling guide
Domestic drinking water testing submission form
Raw water testing submission form
Trade water effluent testing submission form

Water Testing Brochure