6.1. ERMUSR 03-18-2003 Ji
Elk River
Municipal Utilities
322 King Avenue phone: 763.441.2020
Elk River,MN 55330 Fax:763.441.3099
March 5, 2003
To: Elk River Municipal Utilities Commission
James Tralle
John Dietz
Jerry Takle
From: Bryan C. Adams
Subject: Water Production Meters
Staff has been concerned about the accuracy of the water meters at our water production
facilities. The difference between water produced and water sold with even considering other
losses is too great. We had these water production meters tested and the accuracy varies from 5%
to 32%. The problem is the build up of manganese on the meter wall and turbine which causes
the meter to run fast. Other water utilities are also experiencing this problem. Production meter
inaccuracies in the 50% range are not uncommon.
The solution is to replace the existing turbine meter with magnet flow or sonic type
meters with teflon coated walls to minimize the build up of manganese. The most inaccurate
meters are located in facilities 2,3, and 6. The estimated cost to replace these meters is $11,000.
Staff recommends these meters to be replaced. Because the cost exceeds $10,000 and is a non-
budgeted item, this commission must approve the expenditure.
Staff is also looking at a water meter replacement program for the smaller customer
meters. These meters will tend to run slower over time. The large customers meters are tested on
a 3 to 5 year interval to verify accuracy.