CWR - Taxpayers

All collection systems are inefficient and not performing as designed
There can be a significant dollar cost to rate payers resulting from that inefficiency, including the costs related to sewer spills and overflows
As time goes by, the problems get worse and the costs of the inefficiency (and cost to fix) go up
Municipalities often have little choice but to build expensive "downstream" solutions (e.g., storage or expand treatment plants) to solve an "upstream" problem (e.g., collection systems not performing as designed)

CWR provides a viable, cost-effective, performance-based alternative that allows municipalities to
"fix the problem at the source" and to do so in a much shorter period of time.

Why Do All Collection Systems Waste Taxpayer Money?

A sewer system is made up of a collection system and a treatment system. A sewer collection system is comprised of many "basins", which may also be called sub-basins or mini-basins. In simple terms, a basin provides the wastewater infrastructure for a number of customers in a defined area and feeds into a larger sewer main. A basin generally covers an area of 50-100 acres or 100-300 customers. A city or sewer district may have anywhere from a few basins to hundreds of basins. By way of example, King County, WA with a service population of approximately 2 million has 775 basins, (which they term “mini basins”).

The performance and efficiency of a sewer system is dependent on the condition of its collection system, which includes its pipes, manholes and service laterals. The problem is that many sewer collection systems are more than 50 years old - at or beyond their original design lives - and very inefficient. The inefficiency of the collection systems leads to significant "excess I/I" which requires (everyday, ongoing and unnecessary) treatment expense for clean water and may utilize all available collection system capacity. In many collection systems, excess I/I may exceed target or design flow volumes by factor of 2-3x on an "everyday" basis and up to 10x during wet weather events.

In events of maximum/excess capacity, no more water (clean or sewage) can enter the system and discharges result. These discharges of contaminated water occur in basements, streets and/or public water ways. These discharges are unacceptable to citizens, environmental groups and the EPA and are increasingly expensive to respond to - and the real problem may not even be addressed after significant dollars are spent.

Infiltration is the seepage of groundwater into sewer pipes through cracks and joints. Inflow is typically flow from a single point, such as a discharge from sump pumps and foundation drains, or stormwater entering openings in the sewer access covers. This water is considered an unnecessary addition to the volume of water being conveyed by the sewer.

Inflow during major rainfall events results in large quantities of flow entering the system very quickly in time periods that vary from a few hours to several days. During these periods, a sewer system is taxed to the limits, causing hydraulic surcharging, system backups and wastewater flow bypass to occur. These high-peak events consume a large percentage of the available capacity within a sewer system and limit the available capacity needed to serve projected growth needs for a region.

The addition of clear water into a local sewer system creates a number of problems. The additional flow takes capacity that was originally designed for growth and, in some cases, the flow exceeds the available sewer system capacity. When the capacity of the sewer is exceeded, the wastewater back up into basements or spills out of a manhole. These occurrences are not allowable under federal and state regulations. Moreover, the sewer authority charges the users the same rate for its clear water as it does for sewage. Communities, therefore, have a fiscal as well as a public policy reason for ensuring that the total system functions effectively and conforms to federal and state regulations.