In response to the public health threat from rising nitrate-nitrogen levels in increasing numbers of public supply wells, MassDEP developed this planning tool to assess how land use development decisions impact water quality at the well in a MassDEP-approved Zone II (hydrogeologically defined recharge area to the well). The model is also useful for complying with Groundwater Source Approval Regulations, 310 CMR 22.21, and the State Environmental Code, Title 5, 310 CMR 15.216, in determining flexibility of septic system density requirements within water supply areas.

The user friendly model, computerized by our contractor, Horsley and Witten, Inc., is stand-alone software written for IBM compatible computers operating on a DOS system. Minimum 640K RAM is needed with 350K resident memory storage. This is a DOS application; no other software is required. The program files may be downloaded from this web site at no charge: Web page

The Nitrogen Model disk/documentation package is composed of:

• the nitrogen model program 3.5" computer disk
• an instructional manual
• a guidance document that describes how the model fits into the regulatory framework

For further information please contact Tom Lamonte, DWP, at Thomas.Lamonte@state.ma.us or call 617-292-5532.