From: Mark Brest van Kempen <>
Date: May 6, 2005 10:03:56 AM PDT
To: "Osalbo, Faustino Jun" <>
Cc: "Brooks, Desley" <>, "Nadel, Nancy" <>, "Uzegbu, Marcel" <>, "Estes, Lesley" <>, "Schwarz, Alison" <>, <>, <>, <>, "Neary, Mike" <>, <>, Office of the Mayor <>, <>, <>, "Ward, Ron (PWA)" <>, "Lau, David W" <>, "Sweiss, Fuad" <>, <>, <>, Ralph Kanz <>, "Madison, William" <>, pink nose peterson <>, steve leikin <>
Subject: Chimes Creek turbidity and pumping


Thank you very much for agreeing to look into the very turbid quarry-colored

water that has been following the recent rain showers.

As you mentioned the contractors are pumping again today as they have been

doing throughout the rainy season.

For the sake of interested people with little engineering experience I

wanted to put the pumping in a bit of perspective:

They are pumping at 350 cfm. For the layman that means little but it

translates to:

2618 gallons every minute or:
157,080 gallons every hour or:
1,256,640 gallons for ONE 8 hour day.

There are two systems coming off the quarry: 1) Sub drain water that flows

directly from storm drains into Chimes Creek and 2) Surface run off that is

detained in the pond, filtered then pumped into storm drains to Chimes


In a rain storm the subdrains alone now seem to give off as much or even

more water than the total run off before construction since this system now

has the Ridgemont drainage tied directly in to it.

It would seem that the water detained in the pond is water in excess of

pre-construction run off.

Therefore this project during construction is adding over 1.25 million

gallons of water EVERY DAY into Chimes Creek when pumping occurs which has

been pretty much daily throughout the rainy season (This also assumes that

there is no pumping at night).

This begins to explain the increased erosion that we have seen this year

along our properties.

Once again thank you for looking into the continued problems we are having.
Mark Brest van Kempen
3835 Delmont Ave
Oakland CA 94605
510 568 6889