From: Ward, Ron (PWA)
Sent: Thursday, December 29, 2005 12:11 PM
To: 'Mark Brest van Kempen'; Osalbo, Faustino Jun
Cc: Brooks, Desley; Nadel, Nancy; Uzegbu, Marcel; Estes, Lesley; Schwarz,
Alison; ''; '';
''; Neary, Mike; Office of the Mayor;
''; ''; Lau, David W;
''; ''; 'Barbara Sutherland ';
''; Mirsaeidi, Emad; 'nancy peterson'; Movassaghi,
Maziar; Cappio, Claudia; 'McGill, Phillip'; '';
''; ''; 'Kent Peyton'
Subject: RE: Chimes Creek turbidity and pumping


Thank you for your e-mail dated 12/28/05 expressing your concerns for Chimes

We've had a series of storms pass over in the last 12 days, with rainfall
measured at 7.8 inches since 12/17/05.  The Leona Quarry development project
is actively mitigating the effects of these storms by hydroseeding the
non-vegetated slopes and then covering the hydroseeded areas with erosion
control fabric and straw waddles.  After the recent storms, additional
measures have been taken to prevent erosion and sediment transport to Chimes
Creek.  These additional measures include installation of sheet plastic over
some slopes to collect rain water and discharge it directly into the storm
drains, and adjustment and strengthening of the detention pond discharge

We are continuing to work with the developer of the project to identify and
implement further measures to prevent erosion of the soil at the project

The detention pond is utilized to store water temporarily before discharging
to Chimes Creek.  This allows the heavier soil particles to settle out of
the water before being released to the storm drain.  Also, the developer is
filtering the stored water and releasing it to the storm drain with pumps at
a rate of about 300 gallons per minute.  The detention pond does have limits
to its effectiveness.  Flood control capacity needs to be maintained in the
event of a storm that exceeds the capacity of the storm drain pipe crossing
beneath Freeway 580, leading to Chimes Creek.  To maintain this capacity,
the detention pond is designed to drain water from an outfall structure in
the pond after about six feet of water has been stored in the pond.  This
flood control safety feature supercedes the requirement for turbidity
standards in the released water.

The developer for the Leona Quarry project is filtering and pumping clean
water from the pond as fast as they can to make room in the pond for the
next storm.  This should have a beneficial effect on Chimes Creek by
reducing the peak flows during storms and extending the duration of the
storm water release.  When heavy rains fall on the area, the filters cannot
keep up with the inflowing storm water, and untreated, turbid water is
allowed to overflow the weir in the discharge structure.  The height of this
weir has been carefully adjusted, following the recommendations of the
project hydrologist, to maximize the storage capacity of the detention pond
and minimize the release of turbid water.

Thank you for your patience regarding your question about the Creek
Protection Permit for the Ridgemont Basin portion of the development.  We
have conducted an investigation into the history of this permit, with the
following findings:

*   The Community Economic Development Agency (CEDA) reviewed the
developer's request for a Creek Determination in February, 2005.
*   CEDA officials determined in April, 2005 that a Category 2 permit
was applicable to the work proposed by the developer.
*   The Public Works Agency, Environmental Services Division, reviewed
the permit application in May, 2005 and added the additional requirement
that a Creek Protection Plan be prepared by the developer.
*   The developer submitted the Creek Protection Plan on June 6, 2005.
*   On June 15, 2005 the Public Works Agency issued the Creek Protection
Permit to the developer.
*   The developer began work on the Ridgemont Basin portion of the
project on July 17, 2005.

The developer for the Leona Quarry project has agreed to work with the
property owners that may have suffered damages to their footbridges as a
result of the storm water release on December 18, 2005.  That effort is
expected to commence during the month of January, 2006.

We will provide a response to your concerns about the sanitary sewer running
along Chimes Creek in the near future, after further investigation.

Thank you again for reporting your concerns for Chimes Creek.  The City of
Oakland is committed to protecting the creek and maintaining the pristine
environment we all enjoy.

Ronald Ward, P.E.
Supervising Civil Engineer
PWA Project Delivery Division
(510) 238-6606
(510) 238-6633 (FAX)