Water Pollution From Subdivisions: A Hidden Danger?

Water pollution is the contamination of water bodies, which can negatively impact their use. Water pollution is usually a result of human activities, such as sewage discharges, industrial activities, agricultural activities, and urban runoff, including stormwater. Water pollution may affect either surface water or groundwater, and can lead to the degradation of aquatic ecosystems, the spread of water-borne diseases, and a reduction in ecosystem services such as drinking water. Sources of water pollution are either point sources or non-point sources. Point sources refer to specific locations, such as pipes or channels, from which pollutants are discharged directly into water bodies. In contrast, non-point sources refer to diffuse areas where various pollutants enter the water body, such as runoff from agricultural or residential areas. Nonpoint source pollution is the leading remaining cause of water quality problems, and it can be challenging to control due to its dispersed nature.

Fertilizer and pesticide runoff

Fertilizers and pesticides are among the leading causes of water quality degradation. They are a major source of nutrient pollution, which includes nitrates and phosphates, and can have harmful effects on drinking water supplies, recreation, fisheries, and wildlife.

The physical and chemical properties of pesticides play a significant role in determining their potential for runoff. Highly soluble pesticides, for instance, are more likely to be "picked up" by running water and washed off the treated site. Additionally, pesticides that strongly adsorb (attach) to soil particles will remain in place as long as the soil is not eroded by wind or heavy rain. The persistence of a pesticide also matters; the slower it degrades, the more likely it is to move with runoff water.

To minimize fertilizer and pesticide runoff, it is essential to implement nutrient management practices. This includes targeting fertilizer and manure application through soil testing, crop-specific calibration, and timing applications to maximize uptake and reduce runoff. Using drip irrigation instead of furrow irrigation is another effective strategy, as it allows for better control of pesticide and nutrient levels in irrigation water. Storing livestock manure in designated areas, such as lagoons or covered stockpiles, can also help minimize runoff risks.

By adopting these practices and implementing carefully tailored systems of conservation, we can better control multiple pollutants and protect our valuable water resources from the harmful effects of fertilizer and pesticide runoff.

Sewage discharge

In recent years, there has been growing concern and anger over the level of sewage discharges and the quality of waterways. Data from the Environment Agency revealed that water companies in England spilled raw sewage into rivers and the sea for a record 3.61 million hours in 2024. While rules permit limited sewage discharge during periods of excess rain to prevent inundation of sewage works and potential flooding, environmental groups have warned that these levels threaten wildlife and pose health risks to swimmers.

Sewage pollution is not just a local issue but a global crisis, with studies showing extensive contamination in terrestrial, aquatic, and marine systems. This pollution elevates concentrations of nutrients, pathogens, endocrine disruptors, heavy metals, and pharmaceuticals in natural ecosystems, threatening biodiversity and ecosystem health. The effects of sewage pollution on natural habitats have prompted calls for cross-disciplinary collaboration between conservationists and the human health sector to address this pressing issue.

To regulate sewage discharge, the Environmental Protection Agency (EPA) in the United States requires municipal wastewater treatment plants and industrial facilities to obtain permits before discharging pollutants into water bodies. However, in 2018, the EPA reported that nearly 11,000 facilities significantly exceeded their permit limits and illegally discharged pollutants. This highlights the ongoing challenge of ensuring compliance and reducing water pollution, which has led to recommendations for improved data collection and monitoring by the EPA.

To address the issue of sewage discharge, new sewage management solutions are emerging, such as waste-free toilets and resource recovery for fuel and drinking water production. Additionally, investments in infrastructure upgrades and efforts to reduce sewage spills, such as the Water (Special Measures) Bill in England, aim to mitigate the impact of sewage pollution on the environment and human health.

Microplastics

There are two types of microplastics: primary and secondary. Primary microplastics are tiny particles and microfibers shed from commercial products such as cosmetics, clothing, and other textiles, as well as fishing nets. Secondary microplastics are the result of the breakdown of larger plastic items, such as water bottles. These plastics can take hundreds or even thousands of years to decompose and, in the meantime, can contain toxic chemicals and contaminants such as per-and polyfluoroalkyl substances (PFAS) and medications.

The non-uniformity of microplastics, varying in shape, density, and size, makes them difficult to detect and treat. Current methods for identifying microplastics in drinking water and wastewater can only detect particles as small as 10-20 micrometers, but it is known that microplastics can occur at even smaller sizes. This lack of detection methods means a significant percentage of microplastics may be going unnoticed, and these smaller particles could be even more toxic than larger pieces.

The impact of microplastics on the environment is a growing concern, and further research is needed to fully understand the long-term effects on freshwater systems and the food chain.

Oil spills

Cleanup and recovery from an oil spill are challenging and expensive. Physical cleanups can be very costly, and even with advanced technology, it is impossible to remove 100% of the spilled oil. The type of oil spilled, water temperature, and the types of shorelines and beaches involved are crucial factors in the cleanup process. Scientists must also be cautious as their actions can sometimes cause more harm than the oil spill itself, as seen in the Exxon Valdez oil spill in 1989, where high-pressure, hot-water hoses used for cleanup caused more damage.

To address oil spills, the Oil Pollution Act of 1990 established that those responsible for spills can be held accountable for paying for cleanup and restoration. This process, known as Natural Resource Damage Assessment (NRDA), involves federal, state, and tribal agencies working together with the responsible party to select restoration projects with public input. Additionally, satellite technology has been used to patrol oceans for pollution, as seen in the case of the Deepwater Horizon oil spill.

Solid waste

Improper solid waste disposal can lead to water pollution in several ways. One common way is through landfill leakage, where waste breaks down and leaches harmful chemicals, such as toxic metals and organic pollutants, into the surrounding soil and groundwater. This contaminated groundwater can then spread these pollutants to streams, lakes, and oceans, rendering them unsafe for human use and damaging aquatic ecosystems.

Another way solid waste pollutes water is through direct dumping into bodies of water. This practice, sometimes intentional, introduces a range of pollutants, including plastics, electronic waste, and hazardous substances, directly into aquatic environments. These pollutants can break down and release toxic chemicals, harming wildlife and rendering water sources unfit for human use.

Additionally, solid waste left on land can be carried by animals, wind, or rainfall into nearby water bodies, becoming a source of water pollution. This type of pollution, known as nonpoint source pollution, is challenging to address as it originates from various diffuse sources rather than a single point source. Nonpoint source pollution includes urban runoff, where rainwater carries pollutants from residential, commercial, and industrial areas into storm drains and, ultimately, into water bodies.

The impact of solid waste pollution on water quality is far-reaching. It contributes to the contamination of freshwater sources, such as rivers, reservoirs, and lakes, making them unfit for swimming, fishing, and drinking. It also affects marine environments, with an estimated 80% of ocean pollution originating from land-based activities. The improper disposal of solid waste poses risks to both human health and the environment, underscoring the importance of effective solid waste management and pollution prevention measures.

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