The elimination of clean water – ground water – surface water from entering the public sewer IS a premier issue for the Authority in order to control costs both short-term and long-term.
During the calendar year 2011, the Gull Lake Sewer and Water Authority initiated a program to locate, find, minimize and/or eliminate Clean Water from entering the public sewer system. Unnecessary clean water from ground water or storm water sources has been determined to represent between 5%-10% of the Authority's annual cost of treatment at the City of Kalamazoo's Reclamation Facility. The elimination of clean water – ground water – surface water from entering the public sewer IS a premier issue for the Authority in order to control costs both short-term and long-term.
Clean Water enters the sewer system from four areas:
(i) “allowable leakage” of a publicly installed sewer system (no perfect joint system),
(ii) inflow (surface water run-off from streets and yards) or infiltration (water seeping
into the below-ground pipe system), collectively called I/I (inflow + infiltration),
(iii) improper or illegal connection of residential and commercial groundwater drainage
via gravity connection or sump pumps connecting to the public sewer,
(iv) incidental roof downspouts, footing drains, driveway storm drains connected to the
public sewer.
For definition, the Authority segregates the areas of Clean Water Elimination as
(a) inflow, (b) infiltration, and (c) illegal; where the first two in the above paragraph
above are “system” problems, the third and fourth are illegal / improper
connections and discharges from residential and commercial premises.
Our initial analysis indicates that our system has 100-200 manholes that take in water run-off (inflow) that need to be sealed, 100-200 minor leaks within the collection piping system (infiltration) that are to be repaired, and 100-300 homes and/or businesses with groundwater systems/sump pumps connected to the public sewer, equating to approximately 10% of our customers. This latter number is an estimated number, and it has been determined that the only way to accurately assess and document the elimination of clean water discharges from customer's premises (homes + businesses) is to seek out and discover the suspect areas of our system, then, using closed circuit tv cameras inserted into the pipes, determine which homes appear to have constant or intermitten clean water discharges, and then require physical in-home inspection (See Residential / Commercial Inspection Program below).
For a great website on inflow and infiltration, visit:
http://www.goldenvalleymn.gov/homeyard/utilities/inflow-infiltration.php
Proposed Program: By a date yet to be determined, we are considering that all homes and businesses for sale within the Authority's district will receive a letter advising them they must have an inspection under the Authority's "Clean Water Elimination Program". A letter will be sent to each home and business for sale -- mailed to both the owner and the listing realtor advising them of the potential liability that an improper or illegal connection for storm water, run-off, or other clean water represents to the seller. A free inspection by qualified technicians will identify any problems. The problems, once identified, must be repaired at owner's expense or alternatively, metered (if chemical addition is evident) and then a Clean Water Certificate of Compliance will be issued by the Authority. The Certificate will expire every 5 years (+/-) and on-going re-inspections will be required upon each sale, in order to prevent alterations and re-connections of these improper connections to the public sewer.