The Aging Water and Sewer Piping Infrastructure of Bloomington, Illinois
Residents of Bloomington, Illinois need only to look in their own backyard to see that the City of Bloomington faces the same challenge with its aging infrastructure.
The extent of the problem is evidenced by four sinkholes opening in Bloomington streets in a single week. City Engineer Kevin Kothe believes the sinkholes were caused by a combination of winter conditions and issues related to aged underground utilities. Sinkholes, caused by aging utility infrastructure, form underneath and eventually cause chunks of the street to fall through.
On March 10, 2014, on Lee Street a tire of a parked car had sunk into the street, which was not there the night before. A public works camera showed that a sewer-related gap had formed where a car was parked and that another gap had formed nearby, but had not come up to the surface. Water had eroded the ground around the sewer lines, cavities formed, and then dirt fell into the sewer, where it was swept away.
On March 11, 2014, a Union Pacific truck was traveling on Locust Street when the rear driver’s side set of tires punched through the street. It was discovered by a Bloomington Water Department repair crew that water leaking from piping infrastructure built in 1903, had caused a cavity under Locust Street.
On March 12, 2014, three were small street cave-ins that took place on Howard Street, West Seminary Street, and Colton Avenue.
On January 21, 2016, CINews reported that the intersection of Market and Evans Street was closed. The director of Bloomington Public Works observed that a water main leak lead to a sewer line collapse and undermined the ground, resulting in the collapse of a 20 foot by 20-foot portion of the street. All of these elements combined to contribute to a huge sinkhole opening in the street. The aging infrastructure, especially the sewer line that was built in the 1850’s, was to blame.
These incidents show that the older parts of Bloomington have vulnerabilities due to an aged sewer and water system. Some of the sinkholes sites had sewer lines built in 1902 and 1903. This number of incidents in a short number of days is alarming and may point toward infrastructure failure as a much larger problem under the streets. This may indicate that the infrastructure in Bloomington is not getting enough attention.
In 2015, the City of Bloomington had private firms specializing in urban sewer and stormwater management do an analysis and develop a Stormwater and Sanitary Sewer Master Plans for future city master planning. The analysis showed sewer lines conditions and problems that require significant attention and investment. One portion of this analysis of the sewer line system focused on rehabilitating older sewer mains.
The analysis highlighted the aging infrastructure and mentioned sinkholes caused by piping failure. The analysis also showed that the city core is where sewer repairs are most needed because that is where sewer construction began in the second half of the 19th Century.
In preparation for regular street resurfacing, a camera was sent through sewer lines on two separate streets. As you look at the attached videos made using Closed Circuit Television (CCTV), under Douglas Street and Roosevelt Avenue, you will see the advanced stage of deterioration of piping located in the city core.
In the overall Stormwater and Sanitary Sewer Master Plans, which has five separate portions, the private firms recommended spending $136 million over the next 20 years. The portion that we are focusing on, aging sewer pipes, total $63 million over the next 20 years, nearly half of the total to be spent and the single costliest item in the master plan. The $63 million would be spent on CCTV investigation followed by the repair of sewer pipes and manholes. Aging sewer pipes can be grouted, patched, lined, and restored to good condition. It was also stated in the report that this method is much less expensive than digging these sewer lines up and replacing them.
The Bloomington map below shows how broad the scope of the problem is in the city core, with many miles of piping being over 100 years old.
Buried No Longer describes five main challenges that will be faced by local city governments and their public works departments:
CYCLE OF PIPING REPLACEMENT, REPAIR, AND NEW PIPE INSTALLATION. A crucial infrastructure challenge occurs year after year is when:
- Old pipes that were laid down in the earliest years of the city come to the end of their useful lives and have to be replaced
- Middle-aged pipes that were laid down just a little bit later come to the end of their lives
- New additional piping must be installed to keep pace with city expansion.
The city is then faced with starting the cycle all over again.
FINANCIAL. It is crucial to determine how to pay for the necessary replacement of existing aging infrastructure, as well as expanding or adding infrastructure to the system due to city expansion. It is necessary to plan for continuous ongoing investment to cover ongoing costs. At the same time, a local government need to plan for one-time capital investment and expenditures, such as rebuilding a treatment plan or replacing water storage tanks. How they go about financing that the problem can use a mixture of things they can use rates, cash reserves, borrow money, bond market, and American Water Works Association financing options.
ADDRESSING INFRASTRUCTURE SOONER RATHER THAN LATER. Many cities are already addressing their infrastructure needs. For those who have not started or those behind the curve, then the problem will only get worse with time. If a city delays, then the need for reinvestment does not go away. If it is deferred for awhile, then ultimately it will reach the point where reinvestment simply cannot be put off any longer. The cost is then likely to be far higher. You can make the investments when they are timely or you can delay and pay much more later. While there is still time to act, even though the costs may be large, there is a payoff for it to be done sooner rather than later.
RESPONSIBLY PASSING IT ON. If a city does not have a water system that can provide water to the community for the schools, fire protection, public health park systems, and many other needs, then the infrastructure will not allow the other pieces of infrastructure to prosper. The previous generation was responsible for putting infrastructure in to benefit the next generation. The responsibility of the current generation is to make the investments necessary to pass the infrastructure on to the next generation in good working order so that they continue to enjoy all of the public benefits.
CONTINUING IMPROVEMENT OF UNDERSTANDING REPLACEMENT DYNAMICS. As large as the cost of reinvestment may be, not undertaking it will be worse in the long run by almost any standard. This suggests that a crucial responsibility for utility managers now and in the future is to develop the processes necessary to continually improve their understanding of the replacement dynamics of their own water systems. Those dynamics should be reflected in an Asset Management Plan (AMP) and, of course, in a long-term capital investment plan.