Many systems have yet to conquer their issues of inflow and infiltration. The excess rainwater, other groundwater sources and runoff following rain events are a regular nuisance to both collection system operators and treatment plant operators. Both systems can become overwhelmed by inflow and infiltration, in some cases skyrocketing up to 2,800 percent or more inflow and infiltration. Although numbers that high are not frequent, for those operators who do experience this, it is not a laughing matter.
Financial constraints, politics, lack of supervision, knowledge and leadership—all play a part in the problem that has been created. Systems know when inflow and infiltration are of major concern and face it every time Mother Nature sends precipitation of any kind. The astronomical costs associated with treating the excess water, the potential for sanitary sewer overflows, fish and other wildlife kills and other environmental issues are all reasons to reduce inflow and infiltration.
One of the best ways to reduce inflow and infiltration is with manhole rehabilitation. This is considered to be the most economical way to get more results or the best-bang-for-your-buck concept. There are many ways to attack this problem. The following link contains case studies that show multiple ways of manhole rehabilitation. Although the Division of Compliance Assistance does not endorse any of the companies or methods, equipment knowledge and case studies can be valuable information used by operators and municipalities to correct issues that they may be having with inflow and infiltration.