Niessen Consultants is a Sole Proprietorship where more than 50 years of engineering experience can be drawn upon to analyze and solve environmental problems. The primary area of activity involves solid waste management and, particularly, incineration and gasification technologies, energy recovery and associated air pollution control. Assignments include process analysis, concept design, permitting, heat and material balances, presentation in public hearings, and employee training assignments involving technical topics where complex issues are presented in usable and understandable form.