Solutions for Contaminants Found in Groundwater:
| Contaminant | Source | Potential Hydrosil Remediation |
| Ammonia | Agriculture, Industrial Activities, Natu ... | HS-100 |
| Arsenic | Mining, Naturally, Industrial Activities | HS-AS |
| Cadmium | Mining, Industrial Activities | HS-MT |
| Chloride | Drinking Water, Industrial Activities | HS-AC |
What are the most common sources of groundwater pollution?
What is the most common source of groundwater contamination?
- Agricultural Chemicals. Agricultural production has been scaled up in most developed nations. …
- Septic Waste. …
- Landfills. …
- Hazardous Waste Sites. …
- Storage Tanks. …
- Atmospheric Pollutants. …
- Underground Pipes. …
- Road Salts.
What are the major sources of groundwater contamination?
The mining rush is overwhelming the environmental concerns. Producing battery-grade lithium carbonate will cause groundwater contamination with metals including antimony and arsenic, according to US environmental impact documents. Hardrock mining of clay dug out from mountainsides comes with tonnes of sulfuric acid used to treat it at source.
How to prevent common waterborne contaminants?
- Thoroughly wash plastic soda bottles or milk jugs with warm, soapy water. Use containers with screw-on tops. ...
- Fill bottles or jugs directly from the faucet. ...
- Store sealed containers in a dark, dry, and cool place.
- If after six months you have not used the stored water, empty it from the containers and repeat steps 1 through 3 above.Bottom of Form
What contaminants may be present in our water?
The following are general categories of drinking water contaminants and examples of each:
- Physical contaminants primarily impact the physical appearance or other physical properties of water. ...
- Chemical contaminants are elements or compounds. ...
- Biological contaminants are organisms in water. ...
What is the most common source of groundwater contamination?
The significant sources of contamination in groundwater are farming chemicals, septic waste, landfills, uncontrolled hazardous waste, storage tanks, and atmospheric pollutants.Agricultural Chemicals. ... Septic Waste. ... Landfills. ... Hazardous Waste Sites. ... Storage Tanks. ... Atmospheric Pollutants. ... Underground Pipes. ... Road Salts.
Does groundwater have contaminants?
Groundwater contamination occurs when pollutants, such as gasoline or pesticides, reach groundwater and render it unsafe or unfit for human use. Any activity that releases chemicals and pollutants into the environment has the potential to contaminate groundwater, and human activity is almost always the culprit.
Which contaminant sinks through groundwater?
Some contaminants are heavier than water and will continue to sink until reaching an impervious surface. These types of substances are often called “sinkers” or DNAPL's (dense non-aqueous phase liquids). Many chlorinated solvents such as perchloroethylene (“per-kloro-ethyl-een”), a cleaning solvent, are sinkers.
What chemicals are in groundwater?
The principal natural chemicals found in groundwater are dissolved salts, iron and manganese, fluoride, arsenic, radionuclides, and trace metals. Both geologic and climatic conditions influence mineral composition.
What are the four contaminants in groundwater?
[7] Find more information about the four major groundwater contaminants: seawater intrusions, nitrates, arsenic, iron.
Why is drinking water contaminated?
They are inorganic compounds, organic and synthetic compounds, such as pesticides, and other contaminants. Because drinking water systems get their water from groundwater (and SW) sources, once the source becomes contaminated, the drinking water can also become contaminated.
Is groundwater a contaminant?
Groundwater contaminants. Pure water contains nothing but the essential chemical elements of water. Drinking water usually carries a certain amount of minerals, which it acquires from its source, treatment, storage, distribution, and household plumbing conditions. These minerals and elements generally occur at very low levels ...
Is groundwater a risk to health?
These minerals and elements generally occur at very low levels and do not pose a significant risk to health. For more information click on Drinking Water Standards. A wide variety of chemicals and compounds can become groundwater contaminants if discharged to the subsurface environment.
What are the factors that determine the quality of groundwater?
The quality of groundwater is determined by the initial quality of water infiltrating the subsurface, its interaction with the subsurface environment and the impact of anthropogenic activities at the surface (agriculture) or in the subsurface (e.g. oil and gas exploration). Therefore the ‘governing factors’ determining the potential threats to the quality of groundwater are the composition and reactivity of the subsurface strata (geogenic contamination) and contaminant sources from land use and other human activities (anthropogenic contamination). As a result, much like surface water, there may be multiple groundwater quality challenges at any given location.
Why is groundwater low in oxygen?
The groundwater environment typically has low oxygen content because of slow, diffusion-controlled exchange with the atmosphere and because of the presence of natural organic matter in the groundwater aquifers, which consumes oxygen. The redox potential is a measure of the relative concentrations of dissolved oxidised and reduced species and is largely controlled by the balance of oxygen and labile organic matter. As for pH, the redox potential may indicate the degree of mobility for some groups of contaminants or the potential for natural attenuation of others. Typically, reducing conditions (i.e. high OM content) lead to an increase in dissolved Fe, Mn, hydrogen sulphide (H2S), As and ammonia (NH4). If dissolved sulphide is present, then a range of trace metal forming sulphide minerals may have very low mobility. Reducing conditions may also indicate a potential for the natural attenuation of nitrate and some organic contaminants.
How does groundwater differ from surface water?
The groundwater environment differs significantly from surface water in ways that are important for the fate of natural and anthropogenic contaminants. It is dark and has no photosynthesis (but bioactivity exists, even though groundwater is aphotic), has a nearly constant temperature, has limited inputs from the surface (e.g. oxygen) and contains 102 to 106 times fewer bacterial organisms. The main source of natural groundwater recharge is precipitation. Most importantly, the groundwater zone has long water residence times, typically years to millennia compared to weeks for streams and rivers. This allows the groundwater time to react with rocks and minerals, which is important for reactions that are often slow. Some reactions, depending on mineralogy, may lead to geogenic contamination (As, Fe, Mn, F, radionuclides, etc.) but in other cases may facilitate natural attenuation of contaminants from the surface. The spatial scale of groundwater contamination largely depends on whether the contamination originates from point sources (e.g. factories) or diffuse sources of regional origin, for example of agricultural or atmospheric origin.
What are the health effects of drinking contaminated water?
Drinking contaminated groundwater can have serious health effects. Diseases such as hepatitis and dysentery may be caused by contamination from septic tank waste. Poisoning may be caused by toxins that have leached into well water supplies. Wildlife can also be harmed by contaminated groundwater. Other long term effects such as certain types of cancer may also result from exposure to polluted water.
Why is groundwater important?
Groundwater is also one of our most important sources of water for irrigation. Unfortunately, groundwater is susceptible to pollutants. Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use.
What can move through the soil and end up in the groundwater?
Materials from the land's surface can move through the soil and end up in the groundwater. For example, pesticides and fertilizers can find their way into groundwater supplies over time. Road salt, toxic substances from mining sites, and used motor oil also may seep into groundwater. In addition, it is possible for untreated waste from septic tanks and toxic chemicals from underground storage tanks and leaky landfills to contaminate groundwater.
Why are road salts used in the ground?
When it rains, these chemicals can seep into the ground and eventually into the water. Road salts are used in the wintertime to put melt ice on roads to keep cars from sliding around. When the ice melts, the salt gets washed off the roads and eventually ends up in the water.
How many abandoned hazardous waste sites are there in the US?
In the U.S. today, there are thought to be over 20,000 known abandoned and uncontrolled hazardous waste sites and the numbers grow every year. Hazardous waste sites can lead to groundwater contamination if there are barrels or other containers laying around that are full of hazardous materials.
Is groundwater part of the hydrologic cycle?
Since groundwater is part of the hydrologic cycle, contaminants in other parts of the cycle, such as the atmosphere or bodies of surface water, can eventually be transferred into our groundwater supplies.
What are the causes of groundwater contamination?
Septic systems are one of the main causes of groundwater contamination in the United States. Septic systems that are improperly designed or maintained can contaminate groundwater with bacteria, viruses, nitrates, and many other unpleasant contaminants.
How are pesticides used in agriculture?
They are not only used in agriculture and by farmers, but also by homeowners, cities, businesses, and even golf courses. As these chemicals accumulate on lawns and crops, they seep into soil and eventually migrate to groundwater. Their pollution is augmented, as some pesticides even release VOCs. If you live in an agricultural area and have a well, your water supply is especially prone to contamination from agricultural runoff, such as nitrates and VOCs.
Is groundwater a hidden resource?
It exists underground in fractures and spaces between rocks and soil known as aquifers, but even though it is out of sight, the importance of groundwater should not be underestimated.
What is groundwater contamination?
Contamination is defined as the introduction of any undesirable physical, chemical or microbiological material into a water source. There are two types of groundwater contamination sources: point sources and non-point sources. Point sources include landfills, leaking gasoline storage tanks, leaking septic tanks and accidental spills;
What are the properties of groundwater contaminants?
There are several properties to consider when looking at groundwater contaminants. Some of these properties include: persistence, adsorption, solubility, volatility and molecular size.
What are non point sources of groundwater?
Non-point sources can be less obvious and can include naturally occurring contaminants, such as iron, arsenic and radiologicals and runoff from parking lots, pesticides and fertilizers that infiltrate the soil and make their way into an aquifer. There are numerous regulations that address both point sources and non-point sources of groundwater contamination. In addition to these regulations, it is important for citizens to become aware of how their actions can affect the groundwater contamination and take action to reduce any potential contamination.
What is the EPA?
The Environmental Protection Agency (EPA) has enacted several programs that are designed to protect groundwater. These programs include the Safe Drinking Water Act (SDWA), the Resource Conservation and Recovery Act (RCRA), the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the Toxic Substance Control Act (TSCA) and the Clean Water Act.
Is there a regulation that addresses groundwater contamination?
There are numerous regulations that address both point sources and non -point sources of groundwater contamination. In addition to these regulations, it is important for citizens to become aware of how their actions can affect the groundwater contamination and take action to reduce any potential contamination.
Is arsenic a source of contamination?
First, the geological formation can be a source of groundwater contamination; there are various rock formations that contain minerals such as calcium, magnesium, iron, arsenic and various radiologicals. While some of the minerals may not cause any known health effects, naturally occurring arsenic and radiologicals are known carcinogens.
Is arsenic a carcinogen?
While some of the minerals may not cause any known health effects, naturally occurring arsenic and radiologicals are known carcinogens. Second, the formation can slow the contaminant or it may have the opposite effect. For example, contaminants can travel more quickly through sand than clay.
What are the three types of contaminants in groundwater?
The numbers of classes of contaminants detected in groundwater are increasing rapidly, but they can be broadly classified into three major types: chemical contaminants, biological contaminants, and radioactive contaminants. These contaminants can come from natural and anthropogenic sources (Elumalai et al. 2020). The natural sources of groundwater contamination include seawater, brackish water, surface waters with poor quality, and mineral deposits. These natural sources may become serious sources of contamination if human activities upset the natural environmental balance, such as depletion of aquifers leading to saltwater intrusion, acid mine drainage as a result of exploitation of mineral resources, and leaching of hazardous chemicals as a result of excessive irrigation (Su et al. 2020; Wu et al. 2015; Li et al. 2016, 2018).
What are the pollutants in groundwater?
Organic pollutants, including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), are common contaminants of anthropogenic origin in groundwater that could cause serious health problems. In this special issue, two articles focused on these organic pollutants. The article by Ololade et al. (2021) reported an investigation into PAHs and PCBs in groundwater near selected waste dumpsites located in two southwestern states in Nigeria. They found that the more water-soluble, low molecular weight-PAHs accounted for more than 61% of the total PAHs detected across all locations, but surprisingly the more highly chlorinated hexa-PCBs dominated the congener profiles. In another paper in this issue by Ambade et al. (2021), the occurrence, distribution, health risk, and composition of 16 priority PAHs were investigated in drinking water from southern Jharkhand in the eastern part of India. These authors found that lower and middle molecular weight PAHs were dominant in groundwater from the study area, but the levels are currently below concentrations that are a carcinogenic risk.
What is groundwater contamination?
Groundwater contamination is a global problem that has a significant impact on human health and ecological services. Studies reported in this special issue focus on contaminants in groundwater of geogenic and anthropogenic origin distributed over a wide geographic range, with contributions from researchers studying groundwater contamination in India, China, Pakistan, Turkey, Ethiopia, and Nigeria. Thus, this special issue reports on the latest research conducted in the eastern hemisphere on the sources and scale of groundwater contamination and the consequences for human health and the environment, as well as technologies for removing selected contaminants from groundwater. In this article, the state of the science on groundwater contamination is reviewed, and the papers published in this special issue are summarized in terms of their contributions to the literature. Finally, some key issues for advancing research on groundwater contamination are proposed.
How does groundwater affect the environment?
Groundwater contamination also can negatively affect the quality of lands and forests. Contaminated groundwater can lead to soil contamination and degradation of land quality. For example, in many agricultural areas in arid regions, high groundwater salinity is one of the major factors influencing soil salinization (Wu et al. 2014). The soluble salts and other contaminants, such as toxic metals, can accumulate in the root zone, affecting vegetation growth. Groundwater contaminants also can be transported by surface water-groundwater interactions, leading to deterioration of surface water quality (Teng et al. 2018).
How many papers are in the special issue of contaminant?
Nineteen papers are included in this special issue. The topics of these papers cover a range of contamination issues, including the sources of geogenic and anthropogenic contamination, seasonal cycles in contamination, human health risks, and remediation technologies. Figure 2illustrates a word cloud generated using the words in the titles and abstracts of the articles in this special issue, showing the most frequently used terms. The word cloud shows that the most frequently used technical terms in the articles are water, risk, metals, nitrate, fluoride, polycyclic aromatic hydrocarbons (PAHs), health, limits, and values. These terms reflect the main topics of the articles, which cover the assessment of the concentrations of trace metals, fluoride, nitrate, PAHs, and other organic contaminants in groundwater and the associated risks to the health of human populations. Some more minor terms, such as geogenic, source, removal, statistical, EWQI, and mobility, indicate that some articles focus on evaluating the sources of groundwater contamination, approaches to groundwater quality assessment, and contaminant remediation techniques. The main contributions of each article in this special issue are summarized below.
What is groundwater used for?
Groundwater is a major source of fresh water for the global population and is used for domestic, agricultural, and industrial uses. Approximately one third of the global population depends on groundwater for drinking water (International Association of Hydrogeologists 2020). Groundwater is a particularly important resource in arid and semi-arid regions where surface water and precipitation are limited (Li et al. 2017a). Securing a safe and renewable supply of groundwater for drinking is one of the crucial drivers of sustainable development for a nation. However, urbanization, agricultural practices, industrial activities, and climate change all pose significant threats to groundwater quality. Contaminants, such as toxic metals, hydrocarbons, trace organic contaminants, pesticides, nanoparticles, microplastics, and other emerging contaminants, are a threat to human health, ecological services, and sustainable socioeconomic development (Li 2020; Li and Wu 2019).
Why is understanding the seasonal and spatial variations in groundwater quality important?
Understanding the seasonal and spatial variations in groundwater quality is essential for the protection of human health and to maintain the crop yields . Subba Rao et al. (2021) used multiple approaches to identify the seasonal variations in groundwater quality and revealed that the groundwater quality for drinking and irrigation purposes was lower in the post-monsoon period relative to the pre-monsoon period. The deterioration of groundwater quality in the post-monsoon period was attributed to contaminant transport occurring through groundwater recharge but also was influenced by topographical factors and human activities.
What are the contaminants in groundwater?
These are known as geogenic contaminants. Two of the most widely documented geogenic contaminants are arsenic and fluoride, although others include iron, manganese, chromium and radionuclides such as uranium, radium and radon. If these naturally occurring groundwater contaminants are present in sufficiently high concentrations, they can lead to serious health problems, such as cancer (e.g. arsenic) or dental and skeletal problems (e.g. fluoride). Elevated iron and manganese concentrations (in association with microbiological action) commonly have aesthetic (orange, red and black staining of clothes and walls) and operational (clogging of boreholes, pumps and water reticulation infrastructure) impacts, the latter of which plays a critical factor in the success of groundwater supply systems and wellfields.
What are the radioactive substances in groundwater?
Rock and soil contain trace amounts of naturally occurring radioactive substances that can accumulate in groundwater and negatively affect its utilization. Most relevant natural radionuclides of concern for water supply are the water-soluble products of the uranium and thorium radioactive series of uranium (238U, 234U), radium (228Ra, 226Ra) and radon (222Rn). However, individual cases of other radionuclide anomalies in groundwater such as highly toxic polonium (210Po) have also been reported. Due to its short half-life (t1/2) of 3.8 days and volatility, 222Radon might be of concern only when the time between groundwater extraction and its use is short.
What are the elements that make up the Earth's crust?
Iron (Fe) and manganese (Mn) are two of the most abundant metals in the Earth’s crust, and usually occur in association. Both elements are present in a range of rock forming minerals in igneous/metamorphic rocks and associated derived sediments and sedimentary rocks. Fe/Mn can also be introduced into various hard rock lithologies via hydrothermal oxide mineralisation in fractured zones, combined with later secondary supergene enrichment by groundwater flowing along preferential fracture paths. The form and solubility of Fe/Mn in groundwater is strongly dependent on the pH and redox potential of groundwater with Fe/Mn being mobile in either acidic or anaerobic groundwaters, with dissolved oxygen, dissolved organic carbon (and associated organic compounds such as humic, fluvic and tannic acids), salinity, sulphur and/or carbonate species also acting as controlling parameters.
Where is fluoride found?
Fluoride (F-) is found in relative abundance in various minerals throughout Earth’s crust. It is widely present in groundwater as a result of geochemical interactions with fluoride-bearing minerals and the presence of geothermal fluids. Because of its small size and charge, fluoride is highly mobile in groundwater, and controlled by the availability of calcium and the pH of the water.
Is arsenic in water bad for you?
In recent decades, arsenic (As) in groundwater supplies has become increasingly recognized as a major health issue. Although not an essential element for humans and animals, exposure often occurs through food, but most commonly through its natural presence in groundwater used for drinking. The health effects of consuming relatively low doses of arsenic over an extended period of time include disorders of the skin and vascular and nervous systems as well as various cancers.
Is chromium a contaminant?
Another potentially hazardous but infrequently monitored geogenic contaminant is chromium (Cr), which is also found in localized anthropogenic contamination associated with industrial activities or mining. In natural settings, high chromium concentrations are found predominantly in mafic aquifers, with mobility being influenced by pH. Geogenic chromium has been reported in aquifers in Europe and North and South America. Although an essential element, high doses of chromium can possibly be carcinogenic, thus the WHO has a set a provisional guideline value of 50 µg/L.
What are the contaminants in groundwater?
Some of the more common natural contaminants include hydrogen sulfide, which often originates as a
What can degrade groundwater?
Any place where surface water makes its way into groundwater, organic chemicals and pathogens potentially can enter (Winter et al., 1998). Inorganic chemicals that occur naturally in soils, sediments, and rocks —for example, dissolved mineral matter—can also degrade the quality of groundwater. Even though groundwater may be plentiful in a particular area, if the quality of the groundwater has been degraded by the entry of contaminants, the aquifer may not be usable as a water supply. Figure 1 shows the locations of more than 4,000 public water wells in California that have been taken out of service in recent years because of contamination. Many surface water reservoirs used as drinking water supplies are fenced to keep people from contaminating the water. Signs warn, for example, that the reservoir is a municipal drinking water supply and that no human access is permitted. Unfortunately, groundwater reservoirs typically are not protected this effectively. Often, land is zoned and developed (or farmed) without considering the underlying groundwater aquifers and the necessity of protecting the aquifer’s recharge areas. Even aquifers that serve as municipal water supplies for thousands of people often are left mostly or entirely vulnerable. Contaminants can enter aquifers by several means, including: • infiltration of surface water through soil, sediments, and rock, • direct flow from surface water (especially in fractured-rock terrain or karst terrain) • direct flow through improperly built wells that become conduits for contamination, or • cross-contamination below the ground surface from other aquifers via the casings (piping) of improperly built wells. Point source contamination comes from specific locations, such as underground storage tanks, septic systems, and landfills. Nonpoint source contamination arises from an influx of pollutants over a large area, such as can occur from agricultural wastes and urban stormwater runoff.
How many landfills are there in California?
California has more than 2,300 active and inactive landfills, most of which are simply large holes in the ground filled with a variety of hazardous and non- hazardous wastes and covered with dirt. Although landfills built after 1984 must comply with design requirements established by the California State Water Resources Control Board (SWRCB) and other agencies, most of California’s landfills were built before 1984 and are leaking contaminants into the groundwater. Some of the more common contaminants from Class 3 landfills (those that accept only municipal solid wastes) are heavy metals, nitrate, and organic compounds, such as petroleum products, solvents, and pesticides. Class 1 landfills are said to be designed to receive and contain hazardous wastes, but some of the older Class 1 landfills, such as Stringfellow in Riverside County and Casmalia in Santa Barbara County, have caused groundwater contamination because minimum standards for liners were not in effect when they were designed. Even landfills built with liners eventually will leak, necessitating some kind of active leachate control system. After hazardous materials were found to be leaking from solid waste disposal sites, the California Legislature enacted a one-time evaluation of all known sites, to determine to what extent wastes are migrating into surface water and groundwater. This evaluation, known as the Solid Waste Assessment Test (SWAT) program, is administered by the SWRCB. The program does not provide for cleanup or source control. The main responsibility for solid waste management and planning rests with local government. This includes permitting, inspections to verify compliance, and enforcement of permit conditions. The California Integrated Waste Management Board establishes statewide policy and reviews local solid waste management plans and permit decisions pursuant to the Solid Waste Management Resource Recovery Act. The California Department of Toxic Substances Control (DTSC) issues permits that impose specific conditions on the way hazardous wastes can be handled, treated, stored or disposed. These permits include conditions requiring waste analysis, recordkeeping, site monitoring, contaminant procedures, site improvements, closure procedures, and financial responsibility. DTSC also has set up a regulatory program to phase out land disposal of certain hazardous waste. DTSC annually conducts inspections of land disposal facilities as part of the EPA’s Resource Conservation and Recovery Act program. In addition to having authority over municipal landfills, the SWRCB and associated regional water quality boards regulate hazardous waste disposal sites to protect water quality. The federal Toxic Substances Control Act (TSCA) also regulates the production and handling of toxic chemicals. With TSCA, EPA has the authority to identify and control chemical products that pose an unreasonable risk to human health or the environment through manufacture, distribution, processing, use, or disposal. EPA can take a variety of steps to protect health and the environment from the introduction or unrestricted use of new chemicals. These steps include: publishing a chemical inventory, gathering information, and examining manufacturing data. All landfills leak, eventually. A well-managed groundwater basin is one that is monitored to detect leaks, so that any harmful leakage can be attended to quickly by the responsible agencies.
How does groundwater enter the aquifer?
Thus, water typically exits the land (and enters seawater) at subsea outcrops of the aquifer. If the original groundwater gradient changes—for example, as a result of pumping—then seawater can intrude into the coastal aquifer. Intrusion of seawater is particularly prevalent in areas where the coastal shelf is narrow, or where submarine canyons breach the shelf. Intrusion of sea water into groundwater can make an aquifer too salty for drinking. It can also make the aquifer’s water too saline to be used for irrigation. Usually, the contaminated parts of an aquifer can be reclaimed, by stopping the intrusion and then promoting natural flushing of the groundwater by fresh sources of water.
What happens when water percolates through soil?
Water percolating through soils picks up naturally- occurring minerals, salts, and organic compounds. As the water migrates downward, the concentrations of dissolved minerals and salts typically increase, a process known as
Where is chromium found?
Chromium is a naturally occurring element that is ubiquitous in the environment. It is found in rocks, soil, plants, animals, and in emissions from volcanoes. The average abundance of naturally occurring chromium is approximately 20 ppm in granitic igneous rocks, 120 ppm in shales and clays, and 1,800 ppm in ultramafic igneous rocks. Average concentration in the continental crust is 125 ppm. Chromium is used for making steel and other alloys, furnace bricks, and dyes, for chrome plating, for leather tanning preserving of wood, and as a rust inhibitor in cooling towers. Chromium is released to the environ- ment through manufacturing processes, disposal of chromium wastes, or burning of fossil fuels (Morry, 1999).
When was chromium required in drinking water?
Municipalities and other suppliers of drinking water have been required since the 1970s to monitor for total chromium. Total chromium consists of chromium III, an essential human nutrient, and dissolved chromium VI (hexavalent chromium). Few data exist regarding the toxicity of dissolved chromium VI; however, it is
