Envirosight’s newest poster details the causes of inflow and infiltration, or I&I. Inflow occurs when water from aboveground sources enters sewer systems through illegal or faulty connections or openings. Infiltration happens when stormwater seeps through cracks, joints or manholes into sewer pipes. Together, I&I consists of water that does not have to be treated but ends up in a treatment plant anyway. 

A California construction crew was excavating and installing sewer and water lines at a construction site when its trench began to collapse. Though the 17-foot deep trench had been benched, a large section of wall sloughed off. Unable to escape, a supervisor was engulfed in the soil and killed. Investigators later found that the trench’s sidewalls had been sloped for Type B soil, but it should have been classified as Type C. The case is still under review.

Sanitary sewer systems are critical to the U.S. economy and to protecting public health and the environment. But because they're hidden from sight, few outside the water and wastewater industry understand their operation. The Environmental Protection Agency (EPA) regulates more than 151,000 public water systems in the United States that serve 90% of Americans—that’s more than 290 million people who rely on sanitary sewers!

The Clean Water Act (CWA) became law in 1948 and quickly created lasting change regarding how we treat our nation’s water systems. The CWA ensures that dangerous pollutants don’t contaminate waterways, keeping them safe for fish, wildlife and people. Water is essential for all living creatures, so maintaining the integrity of our natural water supplies is vital. Waste and contamination are inevitable, but we can control how we respond to it.

On a daily basis, municipal and public works employees report to the streets to maintain our country’s critical infrastructure. In the course of doing their jobs, they contend with a variety of traffic risks. In observance of National Traffic Incident Response Week, Envirosight is offering a FREE Traffic Safety poster that illustrates steps sewer inspection crews and other municipal workers can take to ensure their own safety while working in traffic.

Sewer infrastructure typically runs under streets, so crews who clean, inspect and rehab sewers are routinely faced with traffic hazards as they do their work. The Federal Highway Administration reports that in 2015, a work zone crash occurred once every 5.4 minutes. Taking extra precautions to make these zones compliant with traffic safety regulations is the best way to minimize risk.

Biohazards are everywhere, in every handshake, sneeze and door handle. What matters isn’t where they are, but how you protect yourself against them. For the average person, regular hand-washing and up-to-date vaccinations are ample protection. But, much like people working in hospitals and medical labs, those who work in and around sewers are at an increased risk of infection and disease from biohazard exposure. And, much like doctors and nurses take extra care to limit that exposure, so should wastewater workers take similar precautions.

When a sewer fails, the solution is seldom cheap or easy. Digging it up can be particularly costly, as well as disruptive to residential customers and road traffic. To avoid this, methods have emerged allowing sewers to be fixed without excavation. These methods are referred to collectively as “trenchless technologies.”

No two sewers pipes are alike. Many differ significantly in terms of size (both diameter and length), pipe material, effluent characteristics, service connections, soil composition and water table. Pipes also fail in different ways: they can crack, leak, settle, erode, corrode and collapse. These failures can be localized, or they can be pervasive. Moreover, the goal of rehabilitation can vary to include:

Personal safety precautions are vital in any sort of construction and maintenance setting, even moreso when the work requires entry into confined spaces, which often contain hazards that can be fatal. According to data from the U.S. Bureau of Labor Statistics, an average of 50 workers die every year as a result of hazards in a permit-required confined space. Many of the casualties can be prevented by following established confined space entry protocols.