“Meeting the Continued Requirements of a Process Safety and Risk Management Plan”

This paper will provide an understanding of the complexity and challenges of implementing and maintaining a Process Safety and Risk Management Plan at a large complex water and wastewater treatment facility. This paper will cover the project from conception through implementation and continued maintenance.In order to comply with EPA Federal Regulation Part 68.150 through 68.190 and the Arizona Division of Occupational Safety and Health Standard CFR 29 1910.119 for Process Safety Management of Highly Hazardous Chemicals the City of Scottsdale began a comprehensive plan to develop and implement a detailed Process Safety and Risk Management Plan (PSM/RMP) for its new Water Campus Facility.The City of Scottsdale's Water Campus is a new state of the art, water and wastewater treatment complex located on a 140-acre site in north Scottsdale. It includes a 50 mgd surface water treatment plant, a 12 mgd water reclamation plant; a 10 mgd advanced water treatment plant including microfiltration and reverse osmosis along with 55 recharge vadose zone wells. This paper will highlight the implementation and maintenance of the PSM/RMP associated with this facility. Initial start-up and operation of the facility took place from October of 1998 through June of 1999, during which time the Management Plans were incorporated.The water reclamation plant is designed for a flow 12 mgd. Effluent from the plant meets standards set by the Arizona Department of Environmental Quality, which allow reuse for open access irrigation. Effluent enters a distribution system delivering water to 20 golf courses in north Scottsdale to meet their irrigation demands. The plant relies on a series of sewer pumping stations to provide the flows into the plant.The advanced water treatment plant includes 24, 90M10C Memchor microfiltration units and 10, 1 mgd 3 stage reverse osmosis trains set in a 24-10-5 array with a target of 85% recovery. The microfiltration units are staged in four “6 packs” with the primary function of 2 six packs as pretreatment of the wastewater effluent prior to RO. The primary function of the other six packs is to treat raw surface water (Colorado River water through the Central Arizona Project canal) prior to recharge through the vadose zone wells. The design provides flexibility to operate the entire microfiltration plant with either wastewater effluent or CAP water. This is determined based on wet weather conditions, golf course irrigation demands and our targeted recharge credits. This application is relatively new in the wastewater treatment field. Water streams from the advanced treatment plant are chemically stabilized prior to discharging to a pump station for final distribution to the recharge vadose wells.Associated with the Water Campus is the storage and application of ammonium hydroxide, chlorine, sulfur dioxide and sodium hydroxide. These highly hazardous chemicals are the basis for development of the PSM/RMP. Regulations 40 CFR §§68.58(a) and 68.79(a) (EPA) and 29 CFR 1910.119 state that owners or operators must certify that they have evaluated compliance with the applicable prevention program provisions at least once every three years to verify that established procedures and practices are adequate and are being followed. This paper will also cover the results of the first audit to meet EPA and OSHA requirements.