APPENDIX G 



QUALITY ASSURANCE FOR GROUNDWATER MODELS THROUGH DOCUMENTATION 



J . J . Donohue , IV 



MA Department of Environmental Quality Engineering 



Division of Water Supply 



Boston, MA 



June, 1986 



Mathematical groundwater flow and contaminant transport models are tools 

 frequently applied to the analysis of hydrogeological systems. Due to the 

 ramifications of decisions based upon modeling results, quality assurance 

 measures need to be applied to all hydrogeological investigations that 

 involve modeling. The complete documentation of a modeling project is the 

 primary mechanism to insure the quality of the effort. 



In order to completely describe the application of a mathematical model to 

 the solution of a hyrogeologic problem, the following outlines the tasks 

 which require documentation. For a more comprehensive treatment of this 

 subject see reference by Van der Heijde (1985). 



1 . Purpose 



State the purpose, goals and objectives of the modeling effort. 



2 . Conceptual Model 



Develop and present a conceptual model of the aquifer system and con- 

 tamination problem of concern (i.e., existing distribution of contami- 

 nants and source characteristics). This should include cross-sections 

 and maps at an appropriate scale of the geology and hydrology of the 

 aquifer. Data set strengths and deficiencies should be presented. 



3. Data Collection 



Explain how the data were collected, analyzed and interpreted. Explo- 

 ration methods and data analysis techniques should be presented. The 

 level of confidence in resulting parameter identification should be 

 described. 



4 . Model Description 



Document the groundwater flow and contaminant transport model (code) 

 utilized. The use of well documented, tested and utilized codes is 

 encouraged. The use of custom or altered codes is discouraged. If an 

 altered code is utilized, it should be thoroughly tested against known 

 solutions. The documentation must include the governing equation(s) 

 being solved. 



