Water Sample Collection (refer to "Fees" for price list)
Which water test do I need?
Water used for domestic purposes has three major determinants of suitability - physical, chemical and biological qualities.
The physical attributes can include colour, turbidity (suspended particles), taste, temperature. which affect the aesthetics of the water. Clear, clean, cool water is highly desirable. Many of the physical attributes of any water relate to its source, collection and storage.
The chemistry of the water is related to geology and likely inputs from natural and human developments. For example, hardness is related to calcium and magnesium salts, mostly derived from dissolved rocks. However, contamination by organic compounds such as herbicides and pesticides reflects poor management by the user of these chemicals.
Biological contamination is related to bacteria, viruses and parasites entering the water. Water can be contaminated by bacteria and viruses from the faeces of warm blooded animals or from decaying remains of animals. Parasites may often be present (Cryptosporidium, Giardia), but are difficult to collect and correctly identify. Viruses are very expensive to isolate and identify- that's why virus testing is not done on a regular basis.
On the farm, around the home or at work, water contaminated by animal sources (including humans) usually occurs from faecal contamination, from the geology of the catchment or groundwater aquifer, or from surface activities.
Thus, the choice of water testing depends upon the history of the water resource and the proposed use of the water. The tests of irrigation water are different from those required for water for human consumption. Some tests are very expensive and only warranted where there is a suspicion that contamination has occurred.
While there area Australian Guidelines for Drinking Water, these guidelines cover the whole spectrum of water sources and uses. It is common practice to test only those parameters which affect the quality of the particular resource and its proposed use.
TYPES OF TESTS
Below are the choices offered to clients:
1. Basic water test: for physical and chemical properties for water used for domestic purposes but not for drinking/cooking water. This test also satisfies the requirements for irrigation water. (click here for water sampling brochure)
2. Faecal Coliform Test: to determine whether the sample has been contaminated by faecal matter from warm blooded animals. A leaking septic tank may be suspected of causing a foul taste in the water - the FC test will quickly show whether or not the cause is the septic tank. This test should be performed on all surface waters used for drinking. (click here for bacteria testing brochure)
3. Specialised tests: the type of tests required are specific to the proposed use of the water, or where contamination from specific sources are required. Pesticide, herbicide, fuels: these tests target suspected sources.
4. Trade waste analysis: see under "Effluent"
The basic water test determines the following parameters;
pH, alkalinity, electrical conductivity, total dissolved solids, salinity, chloride, cations (sodium, calcium, potassium, magnesium), sodium adsorption ratio, soluble phosphorus, nitrate, copper, iron, manganese, hardness, sulphate.
Additional tests are available.
For cost of analysis, check current prices under FEES (double click here)
Water Sampling Method
The protocols for taking water samples
are the same as described below for faecal coliforms, except that one litre (1 L) sample
is required and the bottle must be filled to the very top to exclude all air. Only
samples in bottles supplied by Lanfax Labs will be accepted. Samples presented in
reused plastic bottles will not be analysed. Check with the lab staff before taking
a sample. Plastic bottles will be dispatched upon request.
It is expensive to test for all bacteria which are likely to make humans and/or animals sick. Because bacteria grow in colonies, the faecal coliform test accounts for the heat-tolerant bacterial colonies grown in a water sample at 44.5oC over 24 hours.
Faecal coliform are used to indicate the likely risk of water being contaminated, all drinking water samples should have a nil count per 100 mL sample. However, a "nil count" result does not necessarily mean that the water is not contaminated, it only indicates the condition of the water at the time of sampling.
Sources of Contamination
Septic tanks and drainfields leaking into wells, bores and surface streams is a common cause of water contamination. Dead animals in the water supply, runoff containing faeces (manures) entering the well or draining into the bore may also cause contamination. There's considerable bacteria on our skin, so any contact with the water may contaminate it.
Your hands, clothing and other objects may be contaminated by bacteria. DO NOT place fingers into the water sample bottle and DO NOT allow the lip of the bottle to touch the tap while you are filling it.
SAMPLING METHODS (Click here for Procedures for Water Sample Collection)
Groundwater Sampling Method:
Obtain a 250 mL sterile container from Lanfax Laboratories
Open the tap from which you will obtain the sample, allow the water to run for several minutes until the water coming from the tap is a true sample of the groundwater, rather than the water that has been standing in the pipes.
Open the container immediately prior to filling, do not touch any part of the inside of the container or the lid.
Fill the container to a level just above the top rim (container does not need to be full).
Securely cap the container and label with:
Note: Be careful that water leaking around the tap does not wash over the tap and transfer bacteria from the tap into the container.
Time limit for sample storage (including transport)
The sample must to be returned to Lanfax Laboratories within 30 minutes of sampling or immediately packed in ice for periods not exceeding 6 hours. Samples more than 24 hours old are of no value.
The faecal coliform test requires incubation for 24 hours, so sample results will be available within 36 hours from time of delivery.
Surface Water Sampling Method:
The sample must be dispatched as a chilled sample and be received by Lanfax Laboratories within 6 hours of sampling.
NOTE: Where animals are allowed free access
to water resources, or where runoff from pasture enters the water body, it is most
probable that the water will return a positive faecal coliform test. You should consider
whether to proceed or not with the test and, importantly, what is your intended use of the
Other tests are available for special requirements, whether water contaminated by pesticides, herbicides, arsenic, or cadmium. Often tests area required for specialised research or irrigation purposes.
Contact Lab staff to discuss special requirements that you may have. Check under FEES to see the cost of additional tests. Other prices are available on request.
Check the sampling method before you take the sample, as some tests require glass bottles, partly filled bottles or special treatment with chemical stabilisers.
Treating contaminated water
Disinfection by chlorination
Contaminated water is difficult to treat. Viruses and bacteria pass through water filters, even very fine filters. Many parasites may be removed effectively by filtration, but filters also act as breeding grounds for many microbes and may themselves be some of the causes of foul tastes.
Chlorine may be added at the rate of 10 mg
L-1 to water with a pH 6.5 to 7.5 and out of the direct sunlight. As various
chlorine compounds are available, mostly as swimming pool chemicals, the following list
gives an indication of the dose required for treating water for stock.
A swimming pool chlorine test kit is suitable to measure the chlorine dose.
A residual level of 0.1 mg L-1 should remain two hours after treatment.
Where the water is to be used for human consumption, do not use swimming pool chemicals. Boiling provides an easier means of disinfection for drinking water.
Prevention of contamination is the preferred approach and domestic water supplies should be protected from contamination.
Odour and Taste
Carbon filters are efficient at removing odour and taste from drinking water. Special filter cartridges can be fitted to kitchen taps and the water passing through the filter will have odour, taste and most of the heavy metals removed. Such filters should be treated with respect and changed on a regular basis depending upon the quality of the water. It is uneconomic to treat all the water entering the home for taste and odour.
Most of the taste and odour in domestic supplies has an identifiable cause. It makes great sense to treat the cause rather than treat the symptom.