Adding disclaimer

External review draft of products to be formally disseminated

docs/Mainpage.md

@@ -16,10 +16,12 @@ is written in the C Programming Language and released in the Public Domain.
 
 The United States Environmental Protection Agency (EPA) GitHub project code is provided on an "as is" basis and the user assumes responsibility for its use. EPA has relinquished control of the information and no longer has responsibility to protect the integrity, confidentiality, or availability of the information. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply their endorsement, recommendation or favoring by EPA. The EPA seal and logo shall not be used in any manner to imply endorsement of any commercial product or activity by EPA or the United States Government.
 
+This document is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by the U.S. Environmental Protection Agency. It does not represent and should not be construed to represent any agency determination or policy.
+
 ## Major Release Updates 
 
 * [SWMM 5.2.0 Major Updates](./SWMM_5.2.0.md)
 
 
 # Find Out More
-The source code distributed here is identical to the code found at the official [SWMM Website](http://www2.epa.gov/water-research/storm-water-management-model-swmm).
+The source code distributed here is identical to the code found at the official [SWMM Website](http://www2.epa.gov/water-research/storm-water-management-model-swmm).