42 Engineering design services in the field of the construction and technical operation, of water distribution systems, water treatment systems, water purification systems, wastewater treatment systems, wastewater re-use systems, and drinking water treatment systems; Environmental services, namely, technical consulting in the field of environmental science, specifically with regards to inspection, investigation, analysis, planning, supervision, and research relating to environmental protection in the fields of hydrogeology, drinking water treatment, wastewater treatment, water purification, hydrology, waste assessment, waste treatment and wastewater management, bacteriology, and pollution; Environmental services, namely, technical consultation in the field of environmental science for water distribution systems, water treatment, water purification, wastewater treatment, wastewater re-use and drinking water treatment; Design of water distribution systems, water treatment systems, water purification systems, wastewater treatment systems, wastewater re-use systems, and drinking water treatment equipment