At The Chemistry Solutions Company, we believe every human being has a right to clean water. Understanding what might be in your water is the first step towards ensuring its safety. Our comprehensive Water Contaminant Glossary provides clear, concise explanations of common and emerging water contaminants, their potential health effects, and why professional water testing is crucial.
This glossary is designed to empower you with knowledge, whether your water comes from a municipal tap, a borehole, or a rainwater harvesting system in South Africa.
A
- Aerobic Count (Heterotrophic Plate Count – HPC)
- What it is: A general enumeration of the total number of bacteria present in water that grow under oxygenated conditions. It’s not typically a direct health risk itself, but a high count can indicate favourable conditions for bacterial growth, inefficient water treatment, or contamination within the distribution system.
- Why it matters: Can be an indicator of overall water quality deterioration and may mask the presence of more harmful pathogens.
- Testing for it: Included in standard microbiological water tests.
- Alkalinity
- What it is: A measure of the water’s capacity to neutralise acids, primarily due to the presence of bicarbonates, carbonates, and hydroxides. It acts as a natural buffer against pH changes.
- Why it matters: While not a contaminant itself, very low or very high alkalinity can affect the effectiveness of water treatment processes (e.g., coagulation, disinfection) and can influence the corrosivity or scaling potential of water in pipes.
- Testing for it: Included in comprehensive chemical water analysis.
- Alpha Emitters / Gross Alpha Activity
- What it is: A measure of the total radioactivity released by the emission of alpha particles from dissolved radioactive elements (e.g., Uranium, Radium) in water.
- Why it matters: Ingestion of alpha-emitting radionuclides can increase the risk of cancer over a lifetime. This is a screening parameter for radiological contamination.
- Testing for it: Relevant for borehole or well water, particularly in areas with specific geology (e.g., granite).
- Aluminium
- What it is: A common metallic element naturally present in rocks and soil. It can also be introduced into water through industrial discharge, agricultural runoff, or as a residual from water treatment processes where aluminium salts are used as coagulants.
- Why it matters: High levels can cause water discolouration (milky white or grey), lead to scaling in pipes, and affect taste. While essential for certain biological functions, high chronic exposure has been linked to neurological issues. SANS 241 specifies limits for drinking water based on aesthetic and operational considerations.
- Testing for it: Included in inorganic chemical analysis.
- Ammonia (as N)
- What it is: A compound of nitrogen and hydrogen. In water, its presence typically indicates recent pollution from human or animal waste (e.g., sewage, agricultural run-off, failing septic systems) or some industrial activities.
- Why it matters: While not directly toxic at levels commonly found in drinking water, it can lead to taste and odour issues and can interfere with chlorine disinfection processes, potentially leading to the formation of harmful disinfection byproducts (DBPs). It’s a strong indicator of organic pollution and potential pathogen presence.
- Testing for it: Included in chemical water analysis, often alongside nitrates and nitrites.
- Antimony
- What it is: A silvery-white metalloid found in nature and used in various industries (e.g., fire retardants, ceramics, batteries). It can leach into water from natural deposits or industrial waste.
- Why it matters: Toxic at elevated concentrations. Long-term exposure can cause effects on the liver, kidneys, heart, and may contribute to stomach problems.
- Testing for it: Included in comprehensive inorganic chemical analysis, especially where industrial contamination is suspected.
- Arsenic
- What it is: A naturally occurring metalloid found in certain geological formations and minerals. It can dissolve into groundwater, or be introduced through industrial waste, mining activities, or agricultural runoff (from old pesticides).
- Why it matters: Highly toxic and a known human carcinogen, even at low concentrations. Long-term exposure to arsenic can lead to skin lesions, internal cancers (bladder, lung, skin), cardiovascular disease, neurological problems, and developmental effects. SANS 241 has a strict limit.
- Testing for it: Crucial for borehole and well water sources, and areas with historical mining or industrial activity.
- Asbestos
- What it is: A group of naturally occurring fibrous silicate minerals. It can enter water from the degradation of asbestos-cement pipes used in older water distribution systems or from natural deposits.
- Why it matters: The primary health concern related to asbestos is inhalation, leading to lung cancer and mesothelioma. While the health risks from ingesting asbestos in water are less clearly established, some studies suggest a potential increased risk of gastrointestinal cancers.
- Testing for it: Requires specialized analytical techniques; typically done when asbestos-cement pipes are known to be present in the water system.
B
- Bacteria (General)
- What it is: Microscopic single-celled organisms. While many are harmless, the presence of certain types indicates faecal contamination and potential health risks.
- Why it matters: Pathogenic (disease-causing) bacteria like E. coli, Salmonella, and Campylobacter can cause severe gastrointestinal illness, fever, and other serious health problems.
- Testing for it: Our microbiological tests specifically look for indicator bacteria like E. coli and total coliforms.
- Barium
- What it is: A naturally occurring metallic element found in some groundwater sources. It can also be introduced from drilling fluids, industrial waste, or erosion of natural deposits.
- Why it matters: High levels can lead to increased blood pressure, heart rhythm changes, and nerve damage.
- Testing for it: Included in inorganic chemical analysis.
- Benzene
- What it is: A Volatile Organic Compound (VOC) primarily associated with petroleum products (e.g., gasoline leaks from underground storage tanks), industrial solvents, and some chemical manufacturing processes.
- Why it matters: A known human carcinogen. Long-term exposure can cause disorders of the blood, including anaemia and leukaemia. It also imparts a distinct taste and odour.
- Testing for it: Included in VOC analysis, particularly relevant near fuel storage sites or industrial areas.
- Beta Emitters / Gross Beta Activity
- What it is: A measure of the total radioactivity released by the emission of beta particles from dissolved radioactive elements (e.g., Strontium-90, Tritium) in water.
- Why it matters: Ingestion of beta-emitting radionuclides can increase the risk of cancer over a lifetime. This is a screening parameter for radiological contamination.
- Testing for it: Relevant for borehole or well water, especially near areas with geological uranium deposits or specific industrial activities.
- Beryllium
- What it is: A light, strong metal found naturally in some minerals. It is used in aerospace, electronics, and nuclear industries.
- Why it matters: Known to be a human carcinogen primarily through inhalation. Ingestion through water can cause intestinal lesions at high levels.
- Testing for it: Included in comprehensive inorganic chemical analysis, often in industrialised areas.
- Bicarbonate
- What it is: A major component of alkalinity in water, formed from the dissolution of carbonate rocks and the interaction of carbon dioxide with water.
- Why it matters: Not a direct health risk, but contributes significantly to water hardness and alkalinity. It helps buffer pH changes.
- Testing for it: Measured as part of alkalinity and general chemical analysis.
- Boron
- What it is: A naturally occurring element found in some rocks and soils, particularly in arid regions. It can also come from detergents or industrial waste.
- Why it matters: While essential for plant growth, high levels can be toxic to some plants (affecting irrigation water). In humans, very high intake can cause gastrointestinal issues, nausea, and general weakness. SANS 241 has a guideline limit for drinking water.
- Testing for it: Included in inorganic chemical analysis.
- Bromate
- What it is: A disinfection byproduct that can form when bromide (a naturally occurring ion in some waters) is present during the ozonation disinfection process.
- Why it matters: A suspected human carcinogen.
- Testing for it: Relevant for water utilities using ozonation; requires specialised analysis.
- Bromodichloromethane
- What it is: A specific type of Trihalomethane (THM), a disinfection byproduct formed when chlorine reacts with organic matter in water.
- Why it matters: Part of the group of THMs linked to increased cancer risk and other health issues.
- Testing for it: Included in DBP analysis, relevant for chlorinated water supplies.
- Butachlor
- What it is: A herbicide used to control weeds, primarily in rice cultivation.
- Why it matters: Suspected human carcinogen and can cause liver and kidney damage.
- Testing for it: Part of pesticide analysis, relevant in agricultural areas.
C
- Cadmium
- What it is: A toxic heavy metal found naturally in some soils and rocks, often associated with zinc, lead, and copper ores. It is also a common industrial pollutant (e.g., batteries, plastics, pigments, fertilisers, mining).
- Why it matters: Highly toxic. Long-term exposure can cause kidney damage, bone density loss, and is classified as a known human carcinogen.
- Testing for it: Included in heavy metal and inorganic chemical analysis.
- Calcium
- What it is: A common mineral naturally present in water, contributing significantly to water hardness.
- Why it matters: Essential for human health, but high levels contribute to scale buildup in pipes and appliances, and can affect taste.
- Testing for it: Included in general mineral analysis.
- Carbofuran
- What it is: A broad-spectrum carbamate pesticide used to control insects on a variety of field crops.
- Why it matters: Highly toxic; can cause nervous system effects, nausea, vomiting, and diarrhoea.
- Testing for it: Part of pesticide analysis, relevant in agricultural areas.
- Carbon Tetrachloride
- What it is: A Volatile Organic Compound (VOC) formerly used as a dry-cleaning agent, refrigerant, and in fire extinguishers. Now largely phased out due to environmental concerns, but can persist from old spills or leaks.
- Why it matters: A known human carcinogen and can cause liver and kidney damage, and nervous system effects.
- Testing for it: Included in VOC analysis.
- Chloride
- What it is: A common inorganic anion present in most natural waters. High levels often indicate saline intrusion (from coastal areas or geological salt deposits), industrial discharge, or sewage contamination.
- Why it matters: High concentrations can give water a salty taste, increase corrosivity of pipes, and can be indicative of other, more harmful contaminants associated with pollution (e.g., sewage).
- Testing for it: Included in basic chemical water analysis.
- Chlorine (Residual)
- What it is: Chlorine is a disinfectant added to public water supplies to kill harmful bacteria and viruses. Residual chlorine refers to the amount remaining in the water after disinfection to maintain protection in the distribution system.
- Why it matters: While essential for public health protection, very high levels can cause taste and odour issues, and can lead to the formation of disinfection byproducts (DBPs). Low residual chlorine may indicate insufficient disinfection.
- Testing for it: Can be measured with simple test kits and included in baseline water quality checks.
- Chloroform
- What it is: A specific type of Trihalomethane (THM), a disinfection byproduct formed when chlorine reacts with organic matter in water.
- Why it matters: Part of the group of THMs linked to increased cancer risk and and other health issues.
- Testing for it: Included in DBP analysis, relevant for chlorinated water supplies.
- Chlorite
- What it is: A disinfection byproduct that can form when chlorine dioxide is used as a disinfectant, or through the breakdown of chlorate.
- Why it matters: High levels can cause effects on red blood cells and the nervous system.
- Testing for it: Relevant for water utilities using chlorine dioxide.
- Chlorobenzene
- What it is: A Volatile Organic Compound (VOC) used in the production of other chemicals, as a solvent, and in some pesticides.
- Why it matters: Can cause liver and kidney damage, and nervous system effects.
- Testing for it: Included in VOC analysis, relevant in industrial areas.
- Chromium (Total & Hexavalent)
- What it is: Chromium is a metal that occurs naturally in rocks, animals, plants, and soil. It exists in various forms, but chromium (VI) or hexavalent chromium is a highly toxic and mobile form commonly associated with industrial pollution (e.g., tanning, metal plating, textile dyeing).
- Why it matters: Chromium (III) is generally less toxic and an essential nutrient in small amounts. However, chromium (VI) is a known human carcinogen (particularly through inhalation but also through ingestion) and can cause skin irritation, kidney, liver, and nervous system damage.
- Testing for it: Specialised tests are required to differentiate between total chromium and the more dangerous hexavalent chromium.
- Clarity (see Turbidity)
- Cobalt
- What it is: A metallic element found naturally in rocks and soil. It’s used in batteries, alloys, and as a pigment.
- Why it matters: Essential in small amounts (as part of Vitamin B12). However, high levels can cause heart and thyroid problems.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Coliforms (Total, Faecal/Thermotolerant, and E. coli)
- What it is:
- Total Coliforms: A broad group of bacteria found in the environment (soil, vegetation) and in the intestines of warm-blooded animals. Their presence indicates potential contamination from a variety of sources.
- Faecal Coliforms/Thermotolerant Coliforms: A subgroup of total coliforms, specifically found in the faeces of warm-blooded animals. Their presence is a strong indicator of recent faecal contamination.
- E. coli (Escherichia coli): A specific type of faecal coliform bacteria that lives in the intestines of warm-blooded animals, including humans. Its presence is a definitive indicator of recent faecal contamination.
- Why it matters: While total coliforms aren’t always harmful, their presence suggests a pathway for more dangerous pathogens. Faecal coliforms, particularly E. coli, directly indicate faecal contamination and a high risk of disease-causing bacteria (e.g., salmonella, giardia, cryptosporidium, viruses). For drinking water, the presence of E. coli or faecal coliforms is unacceptable.
- Testing for it: Core components of all our drinking water microbiological tests and laboratory analysis.
- Colour (Apparent & True)
- What it is: A physical characteristic of water. Apparent colour includes suspended solids; true colour is due to dissolved substances.
- Why it matters: While often aesthetic, unusual colour can indicate the presence of organic matter (e.g., tannins), metals (e.g., iron, manganese), industrial waste, or other contaminants, potentially affecting taste and odour or signalling pollution. SANS 241 specifies an aesthetic limit.
- Testing for it: Measured as part of physical water quality parameters.
- Conductivity (Electrical Conductivity – EC)
- What it is: A measure of the water’s ability to conduct an electric current, directly related to the concentration of dissolved inorganic solids (salts, minerals, ions).
- Why it matters: High conductivity indicates high levels of dissolved salts, which can affect taste, accelerate corrosion in pipes, and be problematic for certain industrial uses or irrigation. It’s a general indicator of mineral content and can flag unusual changes in water quality, signalling potential contamination.
- Testing for it: Included in basic physical and chemical water analysis.
- Copper
- What it is: A metallic element that can enter drinking water from the corrosion of copper pipes and plumbing fixtures (especially in older homes with lead solder), or from natural deposits and industrial waste.
- Why it matters: Essential in small amounts for human health. However, high levels can cause gastrointestinal distress (nausea, vomiting, diarrhoea), liver damage, and kidney disease. It also causes blue-green stains on fixtures and a metallic taste. SANS 241 sets a guideline limit.
- Testing for it: Important for homes with older plumbing systems; included in inorganic chemical analysis.
- Corrosivity (Langelier Saturation Index – LSI)
- What it is: An index calculated from pH, alkalinity, calcium hardness, total dissolved solids, and temperature to predict whether water is corrosive (acidic, likely to leach metals) or scale-forming (alkaline, likely to cause mineral buildup).
- Why it matters: Corrosive water can leach metals like lead and copper from plumbing into the drinking water. Scale-forming water can cause mineral buildup in pipes and appliances, reducing efficiency and lifespan.
- Testing for it: Calculated from other measured parameters.
- Cryptosporidium
- What it is: A microscopic parasite (protozoan) that causes cryptosporidiosis, a gastrointestinal illness. It is highly resistant to chlorine disinfection and found in water contaminated with faeces.
- Why it matters: Causes severe, prolonged diarrhoea, nausea, vomiting, and fever. It is a major concern for surface water sources and treatment plants.
- Testing for it: Requires specialised and complex laboratory analysis; typically conducted by municipal water suppliers rather than routine household tests.
- Cyanide
- What it is: A rapidly acting, potentially deadly chemical that can exist in various forms. It’s used in some industrial processes (e.g., mining, steel production, plastics manufacturing, photography).
- Why it matters: Highly toxic. Acute exposure can cause rapid breathing, weakness, convulsions, and coma. Chronic exposure can lead to nerve damage, thyroid issues. Strict limits are applied by SANS 241.
- Testing for it: Requires specialised analytical techniques, often relevant in areas with specific industrial activities, particularly mining.
D
- Dibromochloromethane
- What it is: A specific type of Trihalomethane (THM), a disinfection byproduct formed when chlorine reacts with organic matter in water.
- Why it matters: Part of the group of THMs linked to increased cancer risk and other health issues.
- Testing for it: Included in DBP analysis, relevant for chlorinated water supplies.
- Dichloroacetic Acid (DCAA)
- What it is: A specific type of Haloacetic Acid (HAA), a disinfection byproduct formed when chlorine reacts with organic matter in water.
- Why it matters: Part of the group of HAAs linked to potential cancer risk and developmental effects.
- Testing for it: Included in DBP analysis, relevant for chlorinated water supplies.
- 1,2-Dichlorobenzene
- What it is: A Volatile Organic Compound (VOC) used in chemical manufacturing, as a solvent, and in some pesticides.
- Why it matters: Can cause liver, kidney, and nervous system damage. Known to cause taste and odour issues.
- Testing for it: Included in VOC analysis, relevant in industrial areas.
- 1,4-Dichlorobenzene
- What it is: A Volatile Organic Compound (VOC) commonly found in mothballs and air fresheners, also used as a disinfectant and pesticide.
- Why it matters: A suspected human carcinogen and can cause liver and kidney damage. Also responsible for chemical odours.
- Testing for it: Included in VOC analysis.
- 1,2-Dichloroethane
- What it is: A Volatile Organic Compound (VOC) used in the production of PVC plastic and as a solvent.
- Why it matters: A suspected human carcinogen. Can cause nervous system depression and liver and kidney damage.
- Testing for it: Included in VOC analysis, relevant near chemical manufacturing sites.
- 1,1-Dichloroethylene
- What it is: A Volatile Organic Compound (VOC) used in the production of plastics and as a solvent.
- Why it matters: A suspected human carcinogen and can cause liver and kidney damage.
- Testing for it: Included in VOC analysis.
- cis-1,2-Dichloroethylene
- What it is: A Volatile Organic Compound (VOC) commonly found as a breakdown product of other chlorinated solvents.
- Why it matters: Can cause liver and nervous system effects.
- Testing for it: Included in VOC analysis.
- trans-1,2-Dichloroethylene
- What it is: A Volatile Organic Compound (VOC), an isomer of cis-1,2-dichloroethylene, also a breakdown product of other chlorinated solvents.
- Why it matters: Can cause liver and nervous system effects.
- Testing for it: Included in VOC analysis.
- Dichloromethane (Methylene Chloride)
- What it is: A Volatile Organic Compound (VOC) used as a solvent in paint removers, degreasers, and aerosols.
- Why it matters: A suspected human carcinogen. Can cause nervous system depression and affect the liver and heart.
- Testing for it: Included in VOC analysis.
- Disinfection Byproducts (DBPs)
- What it is: A class of chemical compounds formed when disinfectants (like chlorine, chloramine, or ozone) react with naturally occurring organic matter and inorganic compounds in water. Common types include Trihalomethanes (THMs) and Haloacetic Acids (HAAs).
- Why it matters: Long-term exposure to high levels of some DBPs has been linked to an increased risk of bladder cancer, liver, kidney, and central nervous system problems, and adverse reproductive outcomes.
- Testing for it: Crucial for chlorinated municipal water supplies; requires specialised organic chemical analysis.
E
- Endrin
- What it is: A highly toxic organochlorine pesticide, now largely banned but persistent in the environment.
- Why it matters: Extremely toxic; can cause nervous system damage and is a suspected carcinogen.
- Testing for it: Part of comprehensive pesticide analysis, relevant in areas with historical agricultural use.
- Ethylene Dibromide (EDB)
- What it is: A synthetic organic chemical formerly used as a pesticide and lead scavenger in gasoline. It is persistent in groundwater.
- Why it matters: A probable human carcinogen and can cause liver, kidney, and reproductive effects.
- Testing for it: Relevant near old agricultural sites or fuel storage areas; requires specialized organic analysis.
- Ethylbenzene
- What it is: A Volatile Organic Compound (VOC) found in petroleum products and used in the manufacture of styrene.
- Why it matters: Can cause nervous system effects and kidney or liver problems.
- Testing for it: Included in VOC analysis, relevant near fuel spills or industrial sites.
F
- Faecal Coliforms (see Coliforms)
- Fluoride
- What it is: A naturally occurring mineral found in varying amounts in water sources. It can also be added to public water supplies for dental health benefits.
- Why it matters: Optimal levels (around 0.7 mg/L in South Africa, aligned with WHO) help prevent tooth decay. However, excessively high levels (fluorosis) can cause dental mottling (discolouration of teeth) and, at very high concentrations over long periods, can lead to skeletal fluorosis (bone and joint damage). SANS 241 specifies optimal and maximum allowable concentrations.
- Testing for it: Important for both naturally high areas and public water supplies.
G
- Giardia lamblia
- What it is: A microscopic parasite (protozoan) that causes giardiasis, an intestinal illness. It is found in contaminated water and food.
- Why it matters: Causes severe, prolonged diarrhoea, cramps, nausea, vomiting, and fever. It is resistant to normal chlorine disinfection.
- Testing for it: Requires specialised and complex laboratory analysis; typically a concern for surface water sources.
- Gross Alpha Activity (see Alpha Emitters)
- Gross Beta Activity (see Beta Emitters)
H
- Haloacetic Acids (HAAs)
- What it is: A group of disinfection byproducts (DBPs) that form when chlorine reacts with organic matter in water. Examples include monochloroacetic acid, dichloroacetic acid, and trichloroacetic acid.
- Why it matters: Long-term exposure to high levels has been linked to an increased risk of cancer and developmental effects.
- Testing for it: Relevant for chlorinated municipal water supplies; requires specialised organic chemical analysis.
- Hardness (Total)
- What it is: Primarily caused by dissolved calcium and magnesium minerals in water. “Hard water” has high concentrations of these minerals.
- Why it matters: Not a health risk, but causes aesthetic and operational issues. It leads to scale build-up in pipes, appliances (kettles, geysers, washing machines), reduced soap lathering, and can leave mineral spots on dishes.
- Testing for it: Included in general mineral analysis.
- Heavy Metals
- What it is: A broad category of metallic elements that are often toxic even at low concentrations (e.g., lead, mercury, arsenic, cadmium, chromium, copper, zinc, nickel, selenium). They can occur naturally in geology or from industrial pollution, mining, or plumbing corrosion.
- Why it matters: Exposure can lead to a wide range of severe health problems, including developmental issues, neurological damage, kidney and liver dysfunction, and various cancers.
- Testing for it: We offer specific heavy metal testing as part of our comprehensive inorganic analysis.
- Heterotrophic Plate Count (HPC) (see Aerobic Count)
I
- Iron
- What it is: A common metallic element found naturally in groundwater, or introduced from corrosion of iron pipes.
- Why it matters: While not typically a health concern at levels found in drinking water, high iron levels cause aesthetic issues: reddish-brown staining on fixtures, laundry, and dishes, a metallic taste, and turbidity (cloudiness).
- Testing for it: Included in physical and inorganic chemical analysis.
L
- Langelier Saturation Index (LSI) (see Corrosivity)
- Lead
- What it is: A highly toxic heavy metal. In drinking water, it primarily comes from the corrosion of lead-containing plumbing materials (e.g., lead pipes, lead solder in older homes built before approximately 1985, brass fixtures). It does not typically occur naturally in water sources.
- Why it matters: Very dangerous, especially for infants, young children, and pregnant women. Even low levels of lead exposure can cause developmental delays, learning disabilities, behavioural problems, neurological damage, kidney problems, and high blood pressure. SANS 241 has a strict limit.
- Testing for it: Crucial for older homes or areas with old municipal infrastructure.
- Legionella
- What it is: A genus of bacteria found naturally in freshwater environments. They become a health concern when they grow and spread in human-made water systems (e.g., cooling towers, hot tubs, large plumbing systems).
- Why it matters: Causes Legionnaires’ disease, a severe form of pneumonia, and Pontiac fever, a milder flu-like illness. Infection occurs by inhaling contaminated water droplets.
- Testing for it: Requires specialised microbiological testing, usually performed in specific contexts (e.g., commercial buildings, hospitals, large industrial sites) rather than routine residential drinking water.
- Lindane
- What it is: An organochlorine insecticide, now largely banned but persistent in the environment.
- Why it matters: Can cause nervous system effects and is a suspected carcinogen.
- Testing for it: Part of comprehensive pesticide analysis, relevant in areas with historical agricultural use.
M
- Magnesium
- What it is: A common mineral naturally present in water, contributing to water hardness alongside calcium.
- Why it matters: Essential for human health, but high levels contribute to scale buildup and can have a laxative effect.
- Testing for it: Included in general mineral analysis.
- Manganese
- What it is: A naturally occurring metallic element common in groundwater and some surface waters.
- Why it matters: Can cause black staining on fixtures and laundry, a metallic taste, and turbidity. At very high concentrations, long-term exposure can lead to neurological effects, particularly in children. SANS 241 has an aesthetic limit.
- Testing for it: Included in physical and inorganic chemical analysis.
- Mercury
- What it is: A highly toxic heavy metal that can occur naturally but is primarily introduced through industrial discharge (e.g., mining, power generation, waste incineration, some chemical manufacturing).
- Why it matters: Extremely dangerous. Exposure, particularly to organic mercury compounds (which can form in water), can cause severe neurological damage, kidney problems, and developmental issues in foetuses and children.
- Testing for it: Requires specialised analytical techniques, often part of comprehensive heavy metal screening.
- Metolachlor
- What it is: A commonly used herbicide for various crops.
- Why it matters: Suspected human carcinogen and can cause liver and kidney damage.
- Testing for it: Part of pesticide analysis, relevant in agricultural areas.
- Molybdenum
- What it is: A metallic element found naturally in the Earth’s crust and used in steel alloys and some fertilisers.
- Why it matters: Essential in trace amounts, but high levels can be toxic, particularly to livestock, and may cause symptoms like gout-like joint pain in humans.
- Testing for it: Included in comprehensive inorganic chemical analysis.
N
- Nickel
- What it is: A metallic element found naturally in the Earth’s crust and used in many industrial and commercial applications (e.g., stainless steel, batteries, coins).
- Why it matters: Can cause skin allergies (dermatitis). Ingestion of high levels may lead to gastrointestinal distress and kidney problems.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Nitrate (as N)
- What it is: A nitrogen-containing compound, typically indicating agricultural runoff (fertilisers) or sewage contamination (failing septic systems, animal waste).
- Why it matters: High nitrate levels are particularly dangerous for infants under six months (causing “blue baby syndrome” or methemoglobinemia, which affects oxygen transport in the blood) and can also be a concern for pregnant women.
- Testing for it: Crucial for borehole/well water, especially in agricultural areas or near septic systems.
- Nitrite (as N)
- What it is: An intermediate compound in the nitrogen cycle, often forming from the breakdown of nitrate or ammonia. Its presence in drinking water usually indicates recent pollution or an issue with water treatment.
- Why it matters: Like nitrates, nitrites can cause methemoglobinemia in infants. Their presence also signals active pollution.
- Testing for it: Included in chemical water analysis, often alongside nitrates.
O
- Odour
- What it is: A sensory characteristic of water. Can be described as earthy, musty, chlorine, rotten egg, metallic, etc.
- Why it matters: While often aesthetic, unusual odour can indicate the presence of organic matter, hydrogen sulphide, chlorine byproducts, or microbial activity, sometimes signalling pollution or treatment issues.
- Testing for it: Assessed through sensory evaluation; specific chemical tests can identify the compounds causing the issues.
- Organic Matter (Total Organic Carbon – TOC / Dissolved Organic Carbon – DOC)
- What it is: A measure of the total amount of carbon in organic compounds present in water. It comes from decaying plant and animal matter, or industrial sources.
- Why it matters: High organic matter can lead to taste and odour problems, consume disinfectants (reducing their effectiveness), and react with disinfectants (like chlorine) to form harmful disinfection byproducts (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs).
- Testing for it: Measured as part of comprehensive chemical analysis.
P
- Perchlorate
- What it is: An inorganic chemical that occurs naturally in some arid environments and can also be a component of rocket propellants, fireworks, and some fertilisers.
- Why it matters: Can interfere with the thyroid gland’s ability to absorb iodine, potentially affecting metabolism and development, especially in foetuses and infants.
- Testing for it: Relevant in specific industrial areas or regions with natural perchlorate deposits.
- Per- and Polyfluoroalkyl Substances (PFAS)
- What it is: A group of synthetic chemicals known as “forever chemicals” because they break down very slowly over time. They are used in many products, including non-stick cookware, stain-resistant fabrics, and firefighting foams.
- Why it matters: Highly persistent in the environment and the human body. Linked to various health issues, including increased cholesterol levels, effects on the immune system, thyroid hormone disruption, and increased risk of kidney and testicular cancer.
- Testing for it: An emerging contaminant of concern, requiring specialised and often expensive laboratory analysis.
- Pesticides & Herbicides (Specific Compounds e.g., Atrazine, Glyphosate)
- What it is: Synthetic chemicals used in agriculture, homes, and gardens to control pests (pesticides) and weeds (herbicides). They can leach into groundwater or run off into surface water.
- Why it matters: Many are toxic to humans, even at low levels, and can cause a range of health problems including nervous system damage, reproductive issues, hormonal disruption, and various cancers. Specific health effects vary widely depending on the chemical compound.
- Testing for it: Specialised organic chemical analysis is required, often based on suspected contamination (e.g., proximity to farmlands, specific agricultural practices).
- pH
- What it is: A measure of the acidity or alkalinity of water on a scale of 0 to 14, with 7 being neutral.
- Why it matters: While not a contaminant, pH is a fundamental water quality parameter that influences water chemistry and aesthetic properties. Low pH (acidic water, < 7) can cause corrosion of pipes, leading to the leaching of metals like lead and copper. High pH (alkaline water, > 7) can lead to scale formation, affect the effectiveness of disinfectants, and impart a slippery feel or soda taste. SANS 241 specifies an acceptable range (typically 6.0-9.0).
- Testing for it: A fundamental water quality parameter, included in all our tests.
- Phosphates
- What it is: Compounds containing phosphorus. They can occur naturally from rock erosion but are often introduced through agricultural runoff (fertilisers), wastewater discharge (detergents), or industrial processes.
- Why it matters: While not directly toxic in drinking water, high phosphate levels act as nutrients that can promote excessive algae growth (eutrophication) in surface water bodies, leading to oxygen depletion, foul odours, and potential algal toxins.
- Testing for it: Included in chemical water analysis, particularly for surface water sources or those affected by agricultural runoff.
R
- Radium-226 and Radium-228 (Combined Radium)
- What it is: Radioactive elements that are naturally occurring breakdown products of uranium and thorium in rocks and soil. They can dissolve into groundwater.
- Why it matters: Ingestion of these radionuclides increases the risk of bone cancer and other cancers over a lifetime.
- Testing for it: Important for borehole or well water, especially in areas with specific geology (e.g., granite).
- Radon
- What it is: A colourless, odourless, tasteless radioactive gas that occurs naturally from the decay of uranium in soil and rocks. It can dissolve into groundwater, particularly in granite-rich areas.
- Why it matters: The primary health risk from radon is lung cancer from inhaling the gas (released from water during showering, washing dishes). Ingestion of radon in water may also pose a risk of internal cancers.
- Testing for it: Relevant for well/borehole water in areas with specific geology (e.g., parts of the Western Cape, Namaqualand). Requires specialised radiological testing.
- Residual Chlorine (see Chlorine)
S
- Selenium
- What it is: A naturally occurring metalloid found in some soils and rocks. It is also used in electronics, glass manufacturing, and some industrial processes.
- Why it matters: Essential in very small amounts, but toxic at higher concentrations. Long-term exposure can cause hair loss, nail damage, fatigue, and nervous system damage.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Silica (as SiO2)
- What it is: A common mineral compound found naturally in nearly all water sources.
- Why it matters: Not a health concern. However, high levels can contribute to scaling in pipes and boilers, particularly at higher temperatures, and can be problematic for certain industrial processes.
- Testing for it: Included in general mineral analysis.
- Silver
- What it is: A naturally occurring metallic element, also used in photography, electronics, and some disinfectants.
- Why it matters: Not considered highly toxic to humans in drinking water. However, prolonged exposure to high concentrations can cause argyria, a blue-grey discolouration of the skin and eyes.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Sodium
- What it is: A common mineral found naturally in water and can also be introduced from road salts, water softeners, industrial waste, or saline intrusion (coastal areas).
- Why it matters: While essential for human health, very high levels can affect taste (salty) and can be a concern for individuals on low-sodium diets or those with hypertension.
- Testing for it: Included in basic chemical water analysis.
- Strontium
- What it is: A naturally occurring alkaline earth metal found in some rocks and soils.
- Why it matters: High levels can cause bone and tooth development issues, particularly in children.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Sulphate
- What it is: A naturally occurring compound of sulphur and oxygen. It can be found in various minerals (e.g., gypsum) and can also come from industrial discharges or mining activities.
- Why it matters: High concentrations can give water a bitter taste and have a laxative effect, especially for those not accustomed to it. Can also contribute to scaling.
- Testing for it: Included in inorganic chemical analysis.
- Sulphide (as H2S)
- What it is: Hydrogen sulphide gas (H2S) is produced by the decomposition of organic matter under anaerobic conditions (e.g., in groundwater, stagnant pipes) or by certain industrial processes.
- Why it matters: Gives water a characteristic “rotten egg” smell and can be corrosive to metals. While generally not a direct health threat at levels found in drinking water, it indicates potential bacterial activity or geological sources and can affect taste and odour.
- Testing for it: Can be detected by smell, or measured with specific tests.
- Suspended Solids (Total Suspended Solids – TSS)
- What it is: Particles of material suspended in water that can be filtered out. These can include silt, clay, organic matter, and microorganisms.
- Why it matters: Causes turbidity (cloudiness), can harbour bacteria and viruses, protect microorganisms from disinfection, and contribute to scaling or fouling of plumbing and equipment. High TSS often indicates inadequate filtration or erosion.
- Testing for it: Measured as part of physical water quality parameters.
T
- Taste
- What it is: A sensory characteristic of water. Can be described as metallic, salty, bitter, earthy, chemical, etc.
- Why it matters: While not always indicative of a health risk, unpleasant taste can make water unpalatable and can sometimes signal the presence of underlying contamination (e.g., high minerals, organics, chlorine, pollution).
- Testing for it: Often assessed through sensory evaluation, and specific chemical tests can identify the compounds causing the issues.
- Tetrachloroethylene (PCE)
- What it is: A Volatile Organic Compound (VOC) widely used as a dry-cleaning fluid and metal degreaser.
- Why it matters: A probable human carcinogen. Can cause nervous system effects, liver, and kidney damage.
- Testing for it: Included in VOC analysis, relevant near dry-cleaning facilities or industrial sites.
- Thallium
- What it is: A highly toxic heavy metal found in some ores. It can be introduced by industrial processes or coal combustion.
- Why it matters: Extremely toxic. Can cause hair loss, nervous system damage, and effects on the kidneys, liver, and intestines.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Tin
- What it is: A metallic element found naturally in various minerals and used in alloys, coatings, and some chemicals.
- Why it matters: Generally considered low toxicity, but very high levels can cause gastrointestinal upset.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Toluene
- What it is: A Volatile Organic Compound (VOC) found in petroleum products and used as a solvent in paints, glues, and varnishes.
- Why it matters: Can cause nervous system effects, kidney, and liver damage at high concentrations.
- Testing for it: Included in VOC analysis, relevant near fuel spills or industrial sites.
- Total Dissolved Solids (TDS)
- What it is: A measure of the total concentration of all dissolved inorganic and organic substances in water, typically salts, minerals (e.g., calcium, magnesium, sodium), and some dissolved organic matter.
- Why it matters: High TDS often leads to a salty or mineral taste, can cause scaling or corrosive effects, and may indicate the presence of high levels of other specific contaminants. Low TDS can indicate corrosive water. SANS 241 has an aesthetic limit.
- Testing for it: A fundamental water quality parameter, closely related to electrical conductivity.
- Total Organic Carbon (TOC) (see Organic Matter)
- Total Trihalomethanes (TTHMs)
- What it is: The sum of the four primary Trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform). These are disinfection byproducts (DBPs) formed when chlorine reacts with organic matter in water.
- Why it matters: Long-term exposure to high levels has been linked to an increased risk of bladder cancer, liver, kidney, and central nervous system problems, and adverse reproductive outcomes. SANS 241 sets limits for TTHMs.
- Testing for it: Crucial for chlorinated municipal water supplies; requires specialised organic chemical analysis.
- Trichloroacetic Acid (TCAA)
- What it is: A specific type of Haloacetic Acid (HAA), a disinfection byproduct formed when chlorine reacts with organic matter in water.
- Why it matters: Part of the group of HAAs linked to potential cancer risk and developmental effects.
- Testing for it: Included in DBP analysis, relevant for chlorinated water supplies.
- 1,1,1-Trichloroethane (TCA)
- What it is: A Volatile Organic Compound (VOC) formerly used as a solvent for cleaning and degreasing metals.
- Why it matters: Can cause nervous system effects and liver damage.
- Testing for it: Included in VOC analysis.
- 1,1,2-Trichloroethane
- What it is: A Volatile Organic Compound (VOC) used in the production of other chemicals and as a solvent.
- Why it matters: A suspected human carcinogen and can cause liver and kidney damage.
- Testing for it: Included in VOC analysis.
- Trichloroethylene (TCE)
- What it is: A Volatile Organic Compound (VOC) widely used as an industrial solvent for degreasing metal parts and in some adhesives and paints.
- Why it matters: A known human carcinogen. Can cause nervous system effects, liver, and kidney damage.
- Testing for it: Included in VOC analysis, common near industrial sites, landfills.
- Turbidity
- What it is: A measure of the cloudiness or haziness of water caused by suspended particles (e.g., silt, clay, organic matter, microorganisms, colloids).
- Why it matters: Reduces the effectiveness of disinfection by shielding microorganisms from disinfectants, provides a growth environment for bacteria, and affects the aesthetic quality of water. High turbidity is often a sign of inadequate filtration or erosion. SANS 241 has a strict limit for drinking water.
- Testing for it: A key physical water quality parameter.
U
- Uranium
- What it is: A naturally occurring radioactive element found in rocks and soils. It can dissolve into groundwater.
- Why it matters: Can pose both a chemical toxicity risk (primarily to kidneys) and a radiological risk (increasing cancer risk from internal exposure).
- Testing for it: Relevant for borehole or well water, particularly in areas with specific geological formations (e.g., granite, Karoo formations). Requires specialised radiological and inorganic chemical analysis.
V
- Vanadium
- What it is: A naturally occurring metallic element found in some rocks and soils. It is used in steel alloys and some industrial processes.
- Why it matters: Essential in trace amounts for some biological processes. High levels can be toxic, potentially affecting the nervous system, liver, and kidneys.
- Testing for it: Included in comprehensive inorganic chemical analysis.
- Vinyl Chloride
- What it is: A Volatile Organic Compound (VOC) used primarily to make polyvinyl chloride (PVC) plastic. It’s also a breakdown product of other chlorinated solvents.
- Why it matters: A known human carcinogen. Can cause liver damage and nervous system effects.
- Testing for it: Included in VOC analysis, relevant near PVC manufacturing plants or sites with significant chlorinated solvent contamination.
- Viruses
- What it is: Microscopic infectious agents that can cause a wide range of diseases. In water, they are typically introduced through faecal contamination (human or animal).
- Why it matters: Can cause severe gastrointestinal illness (e.g., Norovirus, Rotavirus), Hepatitis A, and other diseases. They are often more resistant to disinfection than bacteria and can be difficult and costly to detect.
- Testing for it: While not routinely tested in general water quality analysis, their potential presence is inferred by the detection of E. coli or faecal coliforms. Specific viral testing requires advanced laboratory methods.
- Volatile Organic Compounds (VOCs)
- What it is: A broad group of organic chemicals that readily evaporate at room temperature. They can enter water from industrial solvents, fuel leaks (e.g., petrol, diesel), pesticides, paints, glues, and some household products. Common examples include Benzene, Toluene, Xylene, Trichloroethylene (TCE), and Tetrachloroethylene (PCE).
- Why it matters: Many VOCs are toxic and can pose significant health risks, including neurological problems, liver and kidney damage, and various cancers, depending on the specific compound and exposure level. They often cause distinct tastes and odours.
- Testing for it: Requires specialised analytical techniques (GC/MS); crucial if contamination from industrial activities, landfills, or fuel spills is suspected.
X
- Xylenes (Total)
- What it is: A group of Volatile Organic Compounds (VOCs) that are isomers (ortho-, meta-, and para-xylene). Found in petroleum products, used as solvents in paints, lacquers, and in the printing and rubber industries.
- Why it matters: Can cause nervous system effects, liver, and kidney damage at high concentrations.
- Testing for it: Included in VOC analysis, relevant near fuel spills or industrial sites.
Z
- Zinc
- What it is: A naturally occurring metallic element found in many minerals. It can also leach from galvanised plumbing (pipes, tanks) or be introduced through industrial activities.
- Why it matters: While essential in small amounts, high levels can cause taste (metallic or bitter) and aesthetic problems (milky appearance, oily film). Very high levels can cause nausea, vomiting, and diarrhoea.
- Testing for it: Included in inorganic chemical analysis.
Important Note: This glossary provides general information. The specific contaminants present in your water will depend on your water source (municipal, borehole, rainwater, spring), local geology, surrounding human activities (agriculture, industry, urbanisation), and the integrity of your plumbing system. The best way to understand your water quality and identify potential risks is through professional water testing.
The Chemistry Solutions Company offers a range of affordable and accessible water testing kits and laboratory services to help you gain peace of mind and identify the right solution for your water needs.
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