Water Quality Monitoring and Evaluation

ENVIROKONSULT™’s water quality monitoring service

is aimed at all water bodies in need of an aquatic health evaluation or a water management plan.  This includes:

  • Groundwater resources;
  • River systems;
  • Wetlands;
  • Point source outflows (municipalities);
  • Compliance monitoring (industry);
  • Ponds (golf course ponds, ponds of homeowner associations, etc.);
  • Urban impoundments (municipalities);
  • Large dams and reservoirs (municipalities and government).

Water User Groups

ENVIROKONSULT™ has extensive experience in the design, implementation, operation and evaluation of water quality monitoring programmes for various water user groups in South Africa and neighbouring countries.  These water user groups include:

  • Domestic use;
  • Agriculture – Irrigation Use (GlobalGAP / EuropGAP certification);
  • Agriculture – Livestock Watering Use;
  • Agriculture – Aquaculture Use;
  • Industrial Use;
  • Recreational Use;
  • Aquatic Ecosystems.

Water Quality Testing

To gain more information on your particular body of water, ENVIROKONSULT™ can conduct a water quality test to determine several key water quality variables. Based on these results, we can then make and implement specific recommendations in order to improve the water quality of your lake or pond.

When conducting a water quality survey some measurements are taken in the field (in situ) with specialised instruments.  However, other variables can only be determined in a water laboratory and water samples need to be collected for this purpose.  Water samples are delivered to three laboratories, depending on the extent of the monitoring action.  The hydrobiology laboratory performs a diverse range of tests including aquatic toxicity testing, aquatic invertebrate assessment, algae and algal toxin monitoring and aquatic bio-monitoring.  The chemistry laboratory perform testing in organic and inorganic chemistry to monitor water quality for parameters such as pesticides, disinfection by-products, hydrocarbons, trace metals, surfactants, ions, turbidity, taste and odour.  The microbiology laboratory performs analyses to determine for the presence of indicator organisms (E. coli, coliforms, coliphages etc.) and analyses pathogens including Cholera, Cryptosporidium and Giardia.

Standard Water Quality Analysis Includes:

Temperature (Ambient and Water)
Water temperature influences almost all other water quality variables and is always the first data collected during a water quality analysis. Water temperature plays an important role in all biological activities and is the main catalyst for algal and aquatic vegetation growth. Temperature also influences the amount of oxygen the water can hold.
Dissolved Oxygen
Dissolved Oxygen (DO) is a measure of the amount of oxygen available to aquatic organisms and is reported as milligrams per liter (mg/L) or percentage saturation (%SAT). Percentage saturation is a measure of the amount of oxygen dissolved in the water relative to the maximum amount of oxygen that can be held in the water at a specific temperature and atmospheric pressure. Colder water can hold more oxygen than warm water. Dissolved oxygen levels fluctuate daily and are usually lowest in the early morning hours. DO does not pose a problem for most fish until levels fall below 4 mg/L. Pond stratification can create distinct DO levels at different depths during the warm summer months.
pH
pH is a measure of the concentration of hydrogen ions present in water. pH determines whether the tested water is acidic (pH<7) or alkaline (pH>7) compared to neutral water (pH=7). Most aquatic organisms prefer pH levels between 6.5 and 9. The pH fluctuates daily due to the complex interactions of the carbonate cycle (photosynthesis and respiration).
Alkalinity
Alkalinity is defined as the quantity of base present in water. The most common bases include carbonates, bicarbonates, hydroxides, and phosphates. Alkalinity is reported as milligrams of calcium carbonate per liter of water (mg CaCO3/L). Alkalinity determines the buffering capacity of a water body. A good buffering capacity absorbs introductions of acids and bases with little change in pH levels.
Hardness
Hardness is a measure of the quantity of divalent ions in water. Alkalinity is closely related to hardness as both are reported as mg CaCO3/L. Hardness levels affect the toxicity of some algaecides, limit phytoplankton (algae) growth and play a role in fish growth.
Visibility
Visibility is measured with the use of a Secchi disc. A white and black disc measuring 200 mm in diameter is lowered vertically through the water column until it can no longer be seen. Suspended particles reduce visibility levels. Therefore, in the absence of turbidity from silt or mud, the Secchi disc serves as the international standard to indicate phytoplankton density.  Most South African dams have a low visibility due to high turbidity initiated by suspended particles or high phytoplankton concentrations as a result of eutrophication.

Specialized Water Quality Analysis Includes

Bacteriology
A variety of pathogenic viruses, protozoa and bacteria may be transmitted by water.  These microorganisms cause diseases such as gastroenteritis, giardiasis, hepatitis, typhoid fever, cholera, salmonellosis, dysentery and infections.  Indicator organisms are used for routine monitoring for the presence of pathogens in water.  These indicator organisms includes: Total coliform bacteria, Faecal coliform bacteria, E. coli and others.

Faecal coliform bacteria can originate from human or animal sources and counts are often higher after rain events. Observed levels in surface waters are not of a concern unless counts exceed 100 colonies per 100 ml of pond/lake water. High levels indicate a sewage leak, animal waste in the catchment or excessively high numbers of waterfowl utilizing the pond/lake (Usually Canadian Geese in our region).

Nutrient Testing
Depending on your situation knowing nutrient levels is critical on determining algae growth. While phosphorus (TP; PO42-) is limiting in most case some times of the year nitrogen (KN, NO2, NO3, NH3) might be limited or the N:P-ratio may be low to favour blue-green bacteria (cyanobacteria) instead of more preferred green algae. For the aesthetic client knowing nutrient levels is valuable to determine best ways to control algae and aquatic vegetation and predict eutrophication related problems in his water body.
Algae ID:
We can determine the algae composition (phytoplankton and macroscopic algae), classification and biomass. If it is determined that you have a high abundance of cyanobacteria it is important to have microtoxin analyses performed. This is critical information for the lake owner as with increased toxicity levels you may need to shutdown primary contact (swimming, skiing, canoeing, etc.) or other recreational activities, else harmful pathogens might cause adverse effects.

Water Quality Reports

ENVIROKONSULT™ has extensive experience in all facets of water quality monitoring for the various water user groups.  We will design and implement your water quality monitoring programme and present you with interpretative water quality reports to suit each individual client’s needs.