Re: Aquifer storage mixing models

["David L Parkhurst" <dlpark@xxxxxxxx>]

> I am about to calculate the effect of storing water in an aquifer for
later
withdrawal. Previous modellers seemed to have used something called
CHILLER, which I
cannot find.

Chiller was written by Mark Reed and could probably do the calculations you
need. It was designed to model high temperature waters that cool as the
water moves up a well, however, it should be adequate for your application
as well. I'm not sure where to go to get the code.


> I see you list ASR as a possible application of PHREEQC.
Can I include in the mixing of the two waters, things like O2 and CO2
degassing / reactions?


PHREEQC can handle 1D advective/dispersive transport with chemical
reactions, including mineral and gas equilibria, ion exchange, surface
complexation, and kinetic reactions. It is possible to model flow in one
direction followed by flow in the other direction. It is possible to use
radial coordinates for ASR-type calculations. There are general mixing
capabilities, but I'll admit that this part could get tricky to implement
correctly. Fixed partial pressures of O2 and CO2 in specified cells is easy
to implement. PHREEQC is a good tool to check out the chemical effects of
reaction and transport. It also has an inverse modeling capability that can
take injected, background, and extracted water and calculate mixing
fractions and chemical reactions that account for the composition of the
extracted water.

I have used the beta version of PHAST, a 3D reactive transport to
investigate an ASR experiment in South Carolina. After working out
reactions with PHREEQC (inverse and 1D), a full 3D model was implemented.


> Any references come to mind where ASR issues have been directly
addressed.

A USGS conference on ASR was held in April. An open file report from the
conference may be available from the USGS, Water Resources Division, Office
of Ground Water. The report is: U.S. Geological Survey Artificial Recharge
Workshop Proceedings, Sacramento, California, April 2-4, 2002, U.S.
Geological Survey Open-File Report 02-89. The report covers many aspects of
ASR and has some case studies. I have a report in the volume on the
Charleston work that is included below as a Word document.

David


(See attached file: parkhurst.doc)

David Parkhurst (dlpark@xxxxxxxx)
U.S. Geological Survey
Box 25046, MS 413
Denver Federal Center
Denver, CO 80225

Project web page: https://wwwbrr.cr.usgs.gov/projects/GWC_coupled

Attachment: parkhurst.doc
Description: MS-Word document