PROJECT was developed to assist EPA's enforcement program in its penalty assessment responsibilities. The PROJECT Model evaluates the after-tax, net present value of supplemental environmental project (SEP). Violators propose SEP's to mitigate their penalty liability. SEP's are appearing with increasing frequency in enforcement negotiations. In addition, SEP's allow the Agency to effect some extra environmental improvement. The model allows personnel without any background in accounting or corporate finance to determine the real cost of a SEP to defendant for settlement purposes. It prompts the user for costs, dates and certain interest and tax rates. It then calculates the actual cost of a SEP to a defendant by reducing the costs of the project to reflect its tax consequences and net-present value. Projected users of this model are the citizen environmental groups, attorneys representing defendants in enforcement actions, and corporate officials with enmvironmental responsibilities. The software will allow them to easily evaluate proposed SEP's in the same way the EPA evaluates them. This provides clearer communication among parties involved in compliance issues.