To: Rio Linda Net
Cc: Marshall Davert

The message copied below was posted the day after our Water Board meeting on April 15. It makes incorrect statements and misquotes a speaker at our meeting. It cannot be left to stand without correction.

I verified the exact statements made at the meeting both by review of the video tape and by direct contact with the person quoted incorrectly. I made a transcript of what was actually said, and I have posted it on the web.

My responses follow the copy of the subject message.

Jay O'Brien
 
 

-------- Original Message --------
Subject: Re: [RL] RLECWD meeting tonight
Date: Tue, 16 Apr 2002 13:25:56 -0700
From: Charlea Moore <cgamail@juno.com>
To: riolinda@vrx.net

Hi, Where do we go again???  The Water District is perhaps being a little hasty in making their decision to locate a well in an area that may not be safe.  After attending the Water District meeting last night and hearing an explanation of why they are putting a well at that location I can understand it a little better.  Nonetheless, a very knowledgeable gentleman named Marshall made a good presentation on the Hexavalent Chromium hazard. (Think Erin Brockovich)  What was disturbing was when Mary Harris asked if Marshall thought placing a well at that location (28th & Q) was a good idea and Marshall replied "no it wasn't the ideal location."  He thought that the greatest safety lay in the "greatest possible distance" from the hazard area.

Given that - it is fair to say that the greatest distance that will STILL allow the Water District to remedy the pressure problem appears to be the 28th and Q area.  The real question is; Is there a better way to solve the pressure problem in that area?   I think Mary makes a good point in that there is no rush to do this and maybe the new General Manager would have a better solution.  Why not wait another two weeks and let him come on board and maybe come up with a better plan?

Charlea

The very knowledgeable gentleman was Marshall Davert of Montgomery Watson Harza. He did not make the presentation on Hexavalent Chromium as stated by Ms. Moore. The presentation on Hexavalent Chromium was made by Ms. Bonny Starr. Davert's presentation was on the Natomas/RLECWD In-lieu Groundwater Recharge Feasibility Study. The discussion "quoted" by Moore followed Davert's presentation on the feasibility study.

Mary Harris did not specify a location "(28th & Q)" when she asked Davert for his opinion. Harris asked Davert about putting a well within a "couple blocks" of McClellan.

Davert's reply was "I think it would not be a good idea to put a municipal well on the eastern boundary of Rio Linda right up against McClellan Air Force Base. That would be a bad idea."

Davert responded negatively to what he understood to be a proposal to place a well "hundreds of feet away from the Air Force Base and where they have some ongoing remediation", not at any specified location such as 28th & Q Streets. He explained that a half-mile to a mile was reasonable, especially given that different aquifers were involved.

The proposed well location at 24th and Q Streets is two miles north of the groundwater contamination extraction wells on McClellan (OU D) and is over a half-mile from the closest McClellan boundary on Elkhorn Boulevard. It is not a "couple blocks" away as described by Harris.

///end of responses from Jay O'Brien///

See http://obri.net/recall/rlecwd020415.html for transcript.
>From the Rio Linda mailing list

Mary Harris: Marshall, the cone of depression underneath McClellan Air Force Base. If we put a well out there right there within couple blocks of it, would that be doing any good for the District? As far as if were just up on the lip of this depression, that you were saying?

Marshall Davert: I think it would not be a good idea to put a municipal well on the eastern boundary of Rio Linda right up against McClellan Air Force Base. That would be a bad idea.

Harris: One block over would not be a good idea. That would be north.

Davert: Right.

Charlea Moore: It would be north east.

Davert: Yeah.

Harris: Right. So that wouldn't be a good idea.

Davert: I wouldn't think so.

Harris: Ok, that was my thought too. Thank you.

Davert: With a little asterisk: There is multiple aquifers in this basin and most of the municipal wells, as a matter of fact all municipal wells, now by Sacramento County Ordinance, have to be completed and screened, where they draw the water from, in the lower aquifer, called the Mehrten formation, so you are typically down around six hundred feet or so. The contaminants at McClellan are up in the upper, unconfined aquifer, they're typically from about a hundred feet to three hundred feet below the ground surface, so you are pulling from a different aquifer, and then in addition, between those two aquifers, there's some clay layers, there're not totally impermeable, which means nothing gets through, water can migrate between the two, but it is somewhat of a barrier. So if you go deep enough, you don't have to go as far away to be relatively confident you are not pulling the contaminants off McClellan Air Force Base. But, in my mind, there's nothing like distance.

Harris: I agree, I agree.

Doug Cater: But as long as the water quality proves to be ok, yeah fine.

Davert: But there's still nothing like distance.

Cater: There's nothing like distance for that...

Harris (Interrupting): But if you've got new Elverta coming in and they're four thousand new homes...

Cater: Excuse me, I was speaking. When you have a hydraulic problem like we have on that end of the District, we can't push water over there. So to get water over in that area you have to put a well over there. We're not going to pump bad water that's over there it's going to be tested. Adding the well to drill to make sure it's fine. It's not a good idea to put it there, but it's an even a worse idea not to have pressure over there and have low pressure, and get contaminants other ways.

Davert: I was reacting to what was said, "on the border". So I was thinking you were talking hundreds of feet away from the Air Force Base and where they have some ongoing remediation. But if you were, I'd say, a mile away, half a mile to a mile, probably ok, especially if you are in the lower aquifer, because the same concern that you are worried about as if you construct a municipal well and you start drawing water in, you're worried about pulling the contaminants over. The remediation scheme they have on the base, they have created hydraulic "capture zones". Well, they're doing the same thing. They're pumping in certain areas, and they're trying to create little mini cones of depression where they've identified how big is the plume, we put in a well, and we create a cone of depression that's bigger than the plume. So the plume can't get out. It's inside this little cone that's sucking it down to this capture well. So they identified and set up hydraulic capture zones. They do it both ahead of the plume and also down gradient, if anything escapes out, and they have multiple sentinel wells to ensure that it doesn't continue to migrate and get past these capture zones. So just the things that we worry about, they do it in reverse, to try and keep the plumes on the base, and in the remediation capture zones.

End of transcription.

Ensuing discussion on this subject included Mike Phelan, Doug Cater and Ross Hooper.

FACTS:
The McClellan AFB groundwater contamination extraction wells closest to the proposed RLECWD well are in what is called "OU D" on McClellan, for "operable unit D". The extraction wells are just north of Ascot Avenue, east of 20th Street, inside the AFB boundary.

The extraction wells are approximately two miles south of the proposed RLECWD well, tentatively sited at the intersection of 24th Street and Q Street in Rio Linda.

The closest boundary of McClellan AFB to the proposed well site is at Elkhorn Boulevard and 28th Street, a distance of over 3600 feet.