Finding Clean Water Sources: Bacteria And Pollution Awareness

Water is an essential resource for human survival, but unfortunately, billions of people worldwide lack access to clean drinking water. Water can become contaminated with bacteria and other pollutants from natural sources and human activities, posing significant health risks. These contaminants can originate from various sources, including agricultural runoff, industrial waste, sewage treatment facilities, and natural chemical occurrences. The presence of bacteria and pollutants in water sources has severe health implications, causing illnesses such as cholera, typhoid, and gastrointestinal infections, and even leading to deaths. As a result, ensuring safe drinking water and managing water pollution have become critical global challenges.

Industrial and agricultural wastewater

Industrial Wastewater:

Industrial facilities, such as factories, power plants, and manufacturing sites, often generate large volumes of wastewater during their production processes. This wastewater can contain a variety of contaminants, including heavy metals, chemicals, oils, and toxic substances. For example, factories that produce electronics may release wastewater laden with lead, mercury, and other hazardous materials. Similarly, chemical plants can discharge wastewater containing volatile organic compounds (VOCs) and toxic chemicals that are harmful to both the environment and human health.

To prevent the release of contaminated industrial wastewater into natural water bodies, treatment is essential. Industrial facilities are responsible for installing and maintaining proper wastewater treatment systems. These systems employ a range of physical, chemical, and biological processes to remove contaminants and ensure that the treated water meets the required standards before being discharged back into the environment.

Agricultural Wastewater:

Agricultural activities, including livestock operations, crop farming, and the use of pesticides and fertilizers, can also generate significant amounts of polluted wastewater. For instance,

Natural chemicals in groundwater

Natural fresh groundwater contains dissolved elements in three categories: major constituents, minor constituents, and trace constituents. These include major ions, minor constituents, trace elements, organic compounds, and dissolved gases. The amounts of these constituents depend on the climate in the recharge areas, the chemical conditions of the vadose zone, and the geology of the groundwater system through which the water flows.

The natural chemical constituents in groundwater are known as Total Dissolved Solids (TDS). TDS in groundwater is mostly in ionic form, i.e., positively or negatively charged ions. Water with less than 1000 milligrams per liter (mg/L) of TDS is considered fresh, while water with higher TDS is classed as brackish or saline. The TDS level of water changes with depth, from fresh to brackish to saline to brine.

Some natural constituents in groundwater, such as iodine, fluoride, and selenium, can be beneficial at low concentrations but harmful at higher levels. Additionally, the natural presence of chemicals, particularly in groundwater, can be a health concern. For example, arsenic and fluoride are naturally occurring chemicals that can be harmful if present in excessive amounts. Lead is another chemical that may be elevated in drinking water due to leaching from water supply components.

Groundwater can also be contaminated by bacteria, viruses, and parasites, which are collectively known as pathogens. These microorganisms can be found in human sewage, animal waste, and the environment, and they can cause gastrointestinal illnesses and infections. Public water systems are required to regularly test for total coliform bacteria and E. coli to ensure safe drinking water. Private well owners are responsible for protecting and testing their drinking water, as private wells may not receive the same treatment services as public wells.

Sewage treatment facilities

The primary level of treatment typically utilizes screens and settling tanks to separate and remove solid waste from the wastewater. This initial step is crucial for reducing the volume of solid pollutants in the water. Following this, secondary treatment involves the use of biological processes to break down organic matter further. This can be achieved through the use of bacteria that metabolize organics in the wastewater. By allowing a layer of bacteria to grow on rotating disks, the organic pollutants are metabolized and broken down.

Tertiary treatment, also known as effluent polishing, is employed to remove additional suspended solids and organic matter from the secondary effluent. This step often utilizes granular media filters, similar to those used in municipal water supply treatment, to achieve a higher level of purification. It is particularly important when the receiving water body is highly vulnerable to pollution. In some cases, tertiary treatment may also involve removing plant nutrients like nitrates and phosphates, which can cause eutrophication and negatively impact aquatic ecosystems.

While sewage treatment facilities have become more advanced and capable of removing almost all pollutants, the degree of treatment varies depending on local environmental conditions, government standards, and the financial feasibility of implementing costly upgrades. As a result, not all sewage treatment plants are equally effective, and some cities continue to discharge untreated or partially treated sewage into oceans, rivers, and lakes, posing significant environmental and health risks.

Septic systems

The impact of septic systems on water quality depends on several factors, including their design, installation, maintenance, and proper usage. When functioning correctly, a septic system should not adversely affect water quality. However, if the system is failing or outdated, it may discharge untreated wastewater directly into the groundwater or surface waters. This untreated wastewater contains harmful substances such as pathogens (e.g., E. coli), nutrients, and other contaminants.

The contamination of water sources by failing septic systems poses significant health risks to the community. Worldwide, 80% of infectious diseases are water-related, and diarrheal diseases caused by contaminated water claim the lives of approximately 2 million children annually. The bacteria present in wastewater are responsible for diseases such as typhoid, paratyphoid, bacillary dysentery, gastroenteritis, and cholera. Additionally, viruses in wastewater can cause illnesses such as hepatitis A, polio, and viral gastroenteritis.

To prevent the health and environmental hazards associated with failing septic systems, regular maintenance and proper usage are crucial. Homeowners should avoid pouring grease, fats, oils, chemicals, and other harmful substances down the drain, as these can damage the healthy bacteria in the septic tank and contaminate groundwater. Regular inspection, pumping, and maintenance of septic tank systems are essential to prevent wastewater contamination.

In the United States, the Environmental Protection Agency (EPA) provides regulations and programs to address the impact of septic systems on water sources. The Clean Water State Revolving Fund (CWSRF) offers assistance for repairing or replacing failing decentralized systems, and the Nonpoint Source (NPS) voluntary program provides grants and technical assistance to address failing septic systems and other pollution sources.

Stormwater runoff

Sources of bacteria in stormwater include malfunctioning or illicit septic system connections, urban stormwater, manure spills, and agricultural runoff. Sewer overflows, defective septic systems, and the discharge of treated sewage can also introduce bacteria into stormwater. In addition, fecal matter from humans, pets, livestock, and wildlife can contaminate lakes, streams, rivers, and groundwater, leading to the presence of bacteria in stormwater.

The microbial quality of stormwater is often assessed by detecting the presence of fecal indicator bacteria (FIB) such as Escherichia coli (E. coli). The presence of E. coli in stormwater indicates the potential presence of other harmful pathogens. Testing for specific disease-causing organisms can be difficult, expensive, and time-consuming, so E. coli is used as an indicator of water quality.

To manage and reduce bacteria concentrations in stormwater, it is important to identify the sources of contamination and employ specific practices to address them. Upgrading and repairing sanitary sewer and stormwater pipes can help reduce pollutant loads by eliminating leaks. Implementing a treatment train approach, such as the BMP sequence, can also help manage the quantity and quality of stormwater runoff by focusing on pollution prevention, source control, on-site treatment, and regional treatment.

It is important to note that data on the occurrence and levels of pathogens in stormwater runoff is limited due to the challenges of collecting stormwater samples during storm events. However, the potential health risks associated with microbial contaminants in stormwater runoff are significant, and proper management and treatment of stormwater are crucial to ensure safe water supplies for a growing global population.

Frequently asked questions