Sewage treatment and its impact on digestive health are crucial topics that are often overlooked in everyday conversations. However, recent research has shed light on the significant impact that sewer overflows can have on public health, particularly in communities with combined sewer systems. A study led by a team at the School of Public Health at Boston University found that the risk of acute gastrointestinal illness can increase by up to 62% after certain types of sewer overflows.
Combined sewer systems, which were first introduced in the mid-1800s on the East Coast of the United States, combine raw waste and stormwater in the same pipe. While this was a quick solution for rapidly growing cities at the time, it has since been recognized that separating systems based on their contents is more effective. In more modern sewer systems, wastewater, which contains untreated human waste, oil, chemicals, and pollutants, is directed to treatment facilities, while stormwater, the result of storms and rainfall, is discharged into bodies of water without treatment.
The problem arises when combined sewer systems become overwhelmed during heavy rainfall events, leading to combined sewer overflows. This results in untreated wastewater and stormwater being discharged into local bodies of water, contaminating streams and rivers with viruses and bacteria. Outdated combined sewer systems, primarily found in older communities along the East Coast and Midwest, can trigger overflows with as little as 0.3 inches of rain, leading to a heightened risk of gastrointestinal illness for those exposed to contaminated water.
Research has shown a clear association between sewer overflows and gastrointestinal illness, with individuals experiencing symptoms such as vomiting, diarrhea, and infections caused by identifiable pathogens. Studies conducted in various cities across the country have also found an increased risk of gastrointestinal illness following extreme rainfall events that trigger overflows.
Climate change exacerbates the issue by causing more frequent and intense rainfall events, overwhelming drainage systems and increasing the likelihood of sewer overflows. As temperatures rise due to climate change, more water evaporates from the Earth’s surface, leading to heavier downpours and flash flooding. Communities with combined sewer systems are faced with the challenge of mitigating and eliminating these systems, which can be costly and time-consuming.
To combat the impact of sewer overflows, some communities are investing in green infrastructure solutions to reduce the amount of stormwater entering sewers. Strategies such as planting trees, installing rain gardens, and implementing green roofs can help absorb rainwater where it falls, reducing the strain on sewer systems. While these solutions are more cost-effective and quicker to implement than replacing entire sewer systems, more work will be needed to address the challenges posed by climate change.
In conclusion, the link between sewage treatment, sewer overflows, and digestive health is a critical issue that requires attention and action from communities and policymakers. By understanding the impact of combined sewer systems and implementing sustainable solutions, we can work towards a healthier and more resilient future for all.