HomeMy WebLinkAboutIR 8732INFORMAL REPORT TO CITY COUNCIL MEMBERS No. 8732
To the Mayor and Members of the City Council
November 29, 2005
Page 1 of 2
SUBJECT: UPDATE ON WATER DEPARTMENT OPERATIONS
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In early November 2005, the Tarrant Regional Water District requested that the City of Fort Worth
temporarily reduce its intake of raw water from the West Fork of the Trinity River. Because of dry
conditions in recent months, the City was nearing the 100,000 acre feet of water that TRWD allows the
City to take from the West Fork in each calendar year. In order to honor TRWD's request, it was necessary
for the Water Department to realign water sources to the City's four water treatment plants. As a result of
such operational changes, some customers experienced temporary taste and odor problems. The purpose of
this Informal Report is to brief the City Council on the causes and the actions taken to rectify the situation.
Background
The City of Fort Worth purchases raw water from the Tarrant Regional Water District. The water is from
four major sources:
• The West Fork of the Trinity River, via Lake Worth, Eagle Mountain Lake and Lake Bridgeport;
• The Clear Fork of the Trinity River, via Lake Benbrook;
41 • The Cedar Creek Reservoir, located approximately 75 miles southeast of Fort Worth; and
• The Richland Chambers Reservoir, also located approximately 75 miles southeast of Fort Worth
The City has four water treatment plants: Rolling Hills, Eagle Mountain, North Holly and South Holly.
Raw water is piped to these plants, treated and sold to wholesale and retail customers for consumption. As
a general rule, the Rolling Hills plant obtains water from the Cedar Creek and Richland Chambers
Reservoirs and Lake Benbrook; the Eagle Mountain plant obtains water from the West Fork; and the North
and South Holly plants get water from both the West Fork and the Clear Fork. The Rolling Hills and Eagle
Mountain plants use ozone as the primary disinfectant. Ozone is highly effective in controlling taste and
odor. The North and South Holly plants use chloramine as the primary disinfectant and powdered activated
carbon (PAC) for taste and odor control. PAC is not as effective as ozone for taste and odor control.
On Tuesday, November 9, 2005, TRWD requested that the City lower usage from the West Fork sources to
40 million gallons per day (MGD) and that the City limit its intake from the Clear Fork because of low
water levels in Lake Benbrook.
On November 14, it was necessary to take the Eagle Mountain plant out of service for three to four days for
mechanical work. In order to make up for loss of production from the Eagle Mountain plant, the Water
Department increased production at the South Holly plant using water from the West Fork. At that time,
the West Fork pipeline to the South Holly plant had been shut down for four days.
The Water Department took water samples before opening the West Fork pipeline and increased the PAC
sage to help control any taste and odor issues that might arise at the South Holly plant_ Furth,
ximately six hours after the West Fork water pipeline was brought on line at South Holly, Water
Department routine water quality monitoring noted an increase in raw water ammonia, resulting in taste
ISSUED BY THE CITY MANAGER
FORT WORTH, TEXAS
INFORMAL REPORT TO CITY COUNCIL MEMBERS
�I►',Ilk1 .
To the Mayor and Members of the City Council
No. 9 734
Novembe 29, 2005
Pacfe 2 of 2
SUBJECT: UPDATE ON WATER DEPARTMENT OPERATIONS
and odor problems. A change in the chlorine dosage was made immediately in order to maintain the proper
chlorine to ammonia ratio. Once taste and odor problems were detected, additional testing was performed
to verify that the water met all water quality standards and was safe to drink. In addition, to help push the
impacted water through the system, Water Department crews flushed affected lines.
The normal procedure for restarting any raw water source is to flush the pipeline and sample the water
before starting any pumps or opening any valves if the station or source has been off for more than a week.
When a source has been off for more than a week, it is not unusual to experience taste and odor issues.
Further, customers become accustomed to a particular water source and will immediately notice taste and
odor differences upon a change in source water.
Providing high quality drinking water is of primary concern to the Water Department. Although the major
taste and odor problem has been resolved, customers may still notice a slight change in the taste of their
water given the change in source. If you have any questions or need any additional information, please
contact Frank Crumb at 817- 392 -8207.
Charles R. Boswell
City Manager
ISSUED BY THE CITY MANAGER FORT WORTH, TEXAS