Automated Treatment System Used to Solve a Costly and Environmentally Critical Wastewater Problem for an East Coast Utility
Hydrocarbon and particulate contamination in wastewater is a well-known environmental hazard. Due to tightening environmental regulations, an ever-increasing source of such contamination in major cities comes from water collected from underground utility vaults and manhole water. This contaminated water, contains a smorgasbord of potential contaminants from transformers, ground water and sewage ingress and street run-off water containing oils, gasoline, diesel fuel, lubricants, polychlorinated biphenyl’s (PCBs) and other hydrocarbons, as well as soluble and insoluble metals such as lead, mercury, copper, etc. Prior to utility maintenance activity, the water is pumped out of these underground service and maintenance tunnels and must be treated before being discharged back into the municipal sewer system. In many of these cities, the electric utility carries the responsibility for removal and disposal of this contaminated water.
It is not uncommon for the electric utility to collect the contaminated water and haul the untreated water to a third party for processing through a waste water treatment system prior to final disposal. Although these companies are reliable and fully permitted to perform the required services, disposal costs can be high, upwards of $0.20 to $0.30 per gallon. Additionally, if the third party becomes unavailable, for any reason, the consequences for the utility and its customers could be costly from both an environmental compliance and economic standpoint.
As utilities further reduce manpower, the need for a simple, easy to use control system for automating a wastewater treatment system is increasing. Historically, PLC based system have been used to control such processes. However, this requires specialized programming of the PLC for the particular process. Should any changes be required to the control strategy, it requires the end user to contract out a programmer to make these changes at an additional cost. Additionally, if remote communications for monitoring and control are required, additional modules and specialized programming are also required. Thus it is advantageous to be able to employ an off-the-shelf controller with built in, easily changeable control strategies with integrated communications. One such device is the Walchem WebMaster® Series General Industrial Controller (WGI) developed and manufactured by Walchem Corporation in Holliston, Massachusetts. This controller combines flexible, easy to use “Sensor-Control-Relay” mapping integrated with a unique and patented communications technology, ShoulderTap® “Server-On-Demand”, that leverages global communications standards. One example of the WGI used in monitoring and controlling the treatment of wastewater collected by an East Coast Utility from manholes throughout its service territory. A portable system was developed by JoDAN Technologies, LTD of Glen Mills, Pennsylvania and manufactured by Phillips Services Corporation. Equisol, LLC of Conshohocken, Pennsylvania automated and integrated the system, selecting the WGI due to its flexibility and versatility.