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Home » Conference-Details » Workshops » PHREEQ-N-AMDTreat model to evaluate water-quality effects from passive and active treatment of mine drainage

PHREEQ-N-AMDTreat model to evaluate water-quality effects from passive and active treatment of mine drainage


Chuck Cravot­ta | Research Hydrol­o­gist, USGS Penn­syl­va­nia Water Sci­ence Cen­ter
Brent Means | Hydrol­o­gist, OSMRE Pitts­burgh Field Office
Brad Shultz | Min­ing Engi­neer, OSMRE Pitts­burgh Field Office


10:00Overview of AMDTreat 6.0 Beta cost-analy­sis soft­ware (Pow­er­Point)
11:00Overview of AMDTreat 6.0 Beta cost-analy­sis soft­ware (Pow­er Point)
12:00Box lunch pro­vid­ed to reg­is­tered par­tic­i­pants
13:00Live demon­stra­tions of cor­re­spond­ing cost and water-qual­i­ty mod­els for exam­ple pas­sive and active treat­ment sys­tems
14:20Live demon­stra­tions of cor­re­spond­ing cost and water-qual­i­ty mod­els for exam­ple pas­sive and active treat­ment sys­tems
15:30Hands-on par­tic­i­pant tri­als for pro­vid­ed case stud­ies or their own AMD case
16:00Group Ques­tions & Answers and Adjourn


AMDTreat 6.0 Beta (2022) is a new­ly updat­ed com­put­er appli­ca­tion for esti­mat­ing costs and siz­ing facil­i­ties to abate acid mine drainage (AMD) through the appli­ca­tion of pas­sive or active treat­ment tech­nolo­gies. The soft­ware has com­pre­hen­sive cost-analy­sis mod­ules for pas­sive sys­tems, includ­ing ver­ti­cal flow ponds, oxic or anox­ic lime­stone drains, man­ganese removal beds, aer­o­bic or anaer­o­bic wet­lands, and biore­ac­tors, plus active sys­tems, includ­ing caus­tic soda, soda ash, lime prod­ucts, hydro­gen per­ox­ide, per­man­ganate, poly­mer, and ancil­lary com­po­nents such as decar­bon­a­tion (aer­a­tion), con­veyance chan­nels, ponds, and clar­i­fiers. The soft­ware pro­vides over 400 user-mod­i­fi­able vari­ables for exca­va­tion, con­struc­tion, reveg­e­ta­tion, pip­ing, road con­struc­tion, land acqui­si­tion, sys­tem main­te­nance, labor, water sam­pling, design, sur­vey­ing, pump­ing, sludge removal, chem­i­cal con­sump­tion, and oth­er func­tions. The default cost data can be mod­i­fied to adjust for infla­tion or site-spe­cif­ic require­ments. AMDTreat 6.0 also con­tains sev­er­al finan­cial and sci­en­tif­ic tools to help select and plan treat­ment sys­tems. These tools include a long-term finan­cial fore­cast­ing mod­ule, an acid­i­ty cal­cu­la­tor, a sul­fate reduc­tion cal­cu­la­tor, a Lan­ge­li­er sat­u­ra­tion index cal­cu­la­tor, a mass-bal­ance cal­cu­la­tor, and iron oxi­da­tion tools, plus an inte­grat­ed ver­sion of the PHREEQ-N-AMDTreat “TreatTrainMix2” water-qual­i­ty mod­el­ing tool (Cravot­ta, 2020, 2021). The inte­grat­ed PHREEQ-N-AMDTreat tool incor­po­rates all the oth­er sci­en­tif­ic tools into a sin­gle pro­gram to eval­u­ate poten­tial changes in pH, dis­solved met­als, and asso­ci­at­ed solute con­cen­tra­tions result­ing through sequen­tial steps of pas­sive and active treat­ment of AMD.

The inte­grat­ed PHREEQ-N-AMDTreat (TreatTrainMix2) tool and stand-alone PHREEQ-N-AMDTreat tool sets (CausticTitration.exe, ParallelTreatment.exe, and TreatTrainMix2.exe) uti­lize PHREEQC equi­lib­ri­um (aque­ous and sur­face spe­ci­a­tion) and kinet­ics mod­els for gas exchange, iron and man­ganese oxi­da­tion and pre­cip­i­ta­tion, lime­stone dis­so­lu­tion, and organ­ic car­bon oxi­da­tion com­bined with reduc­tion of nitrate, sul­fate, and fer­ric iron. Reac­tions with caus­tic chem­i­cals (CaO, Ca(OH)2, NaOH, Na2CO3) or oxi­diz­ing agents (H2O2) also may be sim­u­lat­ed sep­a­rate­ly or com­bined with sequen­tial kinet­ic steps. A user inter­face for each stand-alone tool facil­i­tates input of water chem­istry and flow data for one or two influ­ent solu­tions and adjust­ment of sys­tem vari­ables, such as gas-exchange kinet­ics, abi­ot­ic and bio­log­i­cal con­tri­bu­tions to iron oxi­da­tion kinet­ics, and lime­stone kinet­ic prop­er­ties, with­out chang­ing the basic PHREEQC cod­ing. Sim­i­lar adjust­ments to key vari­ables can be made with the inte­grat­ed tool. The graph­i­cal and tab­u­lar out­put indi­cates the changes in pH, spe­cif­ic con­duc­tance, total dis­solved solids, alka­lin­i­ty, net acid­i­ty, met­als, and oth­er solute con­cen­tra­tions of treat­ed efflu­ent plus the cumu­la­tive quan­ti­ty of pre­cip­i­tat­ed solids as a func­tion of reten­tion time or the amount of caus­tic agent added. By adjust­ing kinet­ic vari­ables or chem­i­cal dos­ing, the effects of inde­pen­dent or sequen­tial treat­ment steps that have dif­fer­ent reten­tion times (volume/flow rate), aer­a­tion rates, quan­ti­ties of reac­tive solids, and tem­per­a­tures can be sim­u­lat­ed for the spec­i­fied influ­ent qual­i­ty. The size (land area) of a treat­ment sys­tem can be esti­mat­ed using reac­tion time esti­mates for each of the treat­ment sys­tem com­po­nents con­sid­ered in the PHREEQ-N-AMDTreat mod­el. Vol­ume for a cor­re­spond­ing treat­ment step is com­put­ed as the prod­uct of reac­tion time and flow rate; area is com­put­ed as the vol­ume divid­ed by depth. Alter­na­tive­ly, giv­en the esti­mat­ed reac­tion time to achieve the desired efflu­ent qual­i­ty, the AMDTreat cost-analy­sis mod­el may be used to com­pute the size for each sys­tem com­po­nent and the cor­re­spond­ing costs for instal­la­tion (cap­i­tal) and annu­al oper­a­tions and main­te­nance (O&M), with sum­ma­ry results for the net present val­ue of the treat­ment sys­tem as a whole. Thus, var­i­ous pas­sive and/or active treat­ment strate­gies can be iden­ti­fied that could poten­tial­ly achieve the desired efflu­ent qual­i­ty but could require dif­fer­ent land areas, equip­ment, and costs for con­struc­tion and O&M.

Workshop Requirements

Atten­dees are encour­aged to bring a lap­top with AMDTreat 6.0 Beta installed. Links and instruc­tions to down­load the soft­ware are pro­vid­ed below. If you need help please reach out before the con­fer­ence or the day of the work­shop.


AMDTreat 6.0 Beta (2022)
Cravot­ta, C.A. III (2020) Inter­ac­tive PHREEQ-N-AMDTreat water-qual­i­ty mod­el­ing tools to eval­u­ate per­for­mance and design of treat­ment sys­tems for acid mine drainage (soft­ware down­load): U.S. Geo­log­i­cal Sur­vey Soft­ware Release (
Cravot­ta, C.A. III (2021) Inter­ac­tive PHREEQ-N-AMDTreat water-qual­i­ty mod­el­ing tools to eval­u­ate per­for­mance and design of treat­ment sys­tems for acid mine drainage: Applied Geo­chem­istry, v 126, 10845 (

AMDTreat 6.0 Beta and PHREEQ-N-AMDTreat Software Access and Installation

AMDTreat 6.0 Official Web page

The offi­cial web page for AMDTreat 6.0 has links for down­load of the AMDTreat soft­ware, help files, tuto­r­i­al videos, bug lists, and oth­er rel­e­vant infor­ma­tion.

AMDTreat | Office of Sur­face Min­ing Recla­ma­tion and Enforce­ment ( |

AMDTreat 6.0 tuto­ri­als, YouTube by AMDTreat team mem­bers avail­able online |


Before installing and run­ning AMDTreat Beta 6.0 or PHREEQ-N-AMDTreat soft­ware pack­ages, the fol­low­ing pre­req­ui­sites must be installed:

Admin­is­tra­tive priv­i­leges may be required to install the above pre­req­ui­sites.

Next, the zip files, below, that include the AMDTreat 6.0 Beta and PHREEQ-N-AMDTreat soft­ware need to be down­loaded and extract­ed to your com­put­er.

PHREEQ-N-AMDTreat and AMDTreat 6.0 Software for download

AMDTreat 6.0 Beta and the stand-alone PHREEQ-N-AMDTreat soft­ware pack­ages that com­ple­ment the inte­grat­ed tool in AMDTreat 6.0 are avail­able at the FTP link below | TreatTrainMix2.exe, ParallelTreatment.exe, and CausticTitration.exe tools. | TreatTrainMix2REYs.exe and CausticTitrationMix2REYs.exe tools include rare-earth and select­ed trace ele­ments.

AMDTreat 6.0 Beta | Same as AMDTreat 6.0 Beta at OSMRE web page but includes all cur­rent­ly avail­able help files in pdf.

To access any of the above zip files on FTP: Use Win­dows Explor­er to open any fold­er (e.g. Doc­u­ments) on your com­put­er. Copy the above ftp link and paste it into the Doc­u­ments fold­er address bar, then hit return. Con­tents of the FTP fold­er should now show. Copy the select­ed files and paste them on your com­put­er. Admin­is­tra­tive priv­i­leges should not be need­ed.

Once down­loaded, users should unzip or copy the con­tents of the AMDTreat 6.0 to a user direc­to­ry on their local com­put­er, and then find the file called AMDTreat 6.0 Beta.exe and dou­ble-click on it to run. The screen­shot below shows the direc­to­ry tree that will be cre­at­ed and the loca­tion of the exe­cutable file.

Optional – create a shortcut to the executable program on your desktop

Nav­i­gate to the direc­to­ry where installed, and find the file named AMDTreat 6.0 Beta.exe. Right-click on the file and select “send to” from the menu and choose “Desk­top”. You can now run the pro­gram from this icon that has been cre­at­ed on your desk­top