Plant and Equipment

With highly sophisticated equipment and experienced operators, NewStream is able to treat wastewater in the most efficient, and therefore cost effective, manner possible. While NewStream configures the system to best treat each individual waste stream that it receives, the following information provides a step-by-step description of a typical treatment process.

When wastewater is first received at the plant, it is pre-treated to neutralize the pH, remove settleable solids, chelating agents, oil, grease and inert materials, and to generally prepare the waste stream for further treatment. It is then transferred to one of two 250,000 gallon equalization (EQ) storage tanks. At this point in the process, the water may still contain dissolved solids and therefore require secondary treatment through a combination of chemical reactions and physical separation.

Optimal performance during the next stages of treatment can only be achieved when the pH, flow rate, and composition of the wastewater are strictly controlled. Therefore, when the wastewater reaches the EQ tanks, large mixers create a homogeneous composition, and the water re-enters the plant at a constant flow rate, which is adjustable up to 800 gpm to meet throughput demand. Upon re-entering the plant, the wastewater flows into two large inclined plate hydroxide clarifiers. (All of the advanced wastewater treatment unit operations come in pairs. This redundancy minimizes the possibility of total system failure, and allows for ease of maintenance.)

In the clarifiers, one or more chemical coagulants and/or polymers (depending on the wastewater being treated) are injected to precipitate metals and other contaminants out of solution and physically separate these solids from the water by gravity settling. The precipitate forms a sludge, which is periodically pumped out of the clarifiers to large thickening tanks. The thickened sludge is dewatered in recessed chamber filter presses, resulting in a dry filter “cake” that is sent off site to an appropriate sludge disposal and reclamation facility. If the sludge contains valuable metals such as nickel or palladium, these are recovered for re-use in other manufacturing processes.

In order to meet some of today’s water quality criteria-based discharge limits, solids — particularly metals — need to be reduced into the part per billion range. Consequently, the effluent from the clarifiers may be processed through additional unit operations. One of these is the Insoluble Sulfide Precipitator (ISP) process, which is very similar to the chemical reaction that forms the precipitates in the inclined plate clarifiers. The critical distinction is that metal sulfides are much less soluble in water than their hydroxide counterparts. Therefore, the treated water emanating from the ISP precipitators contains only trace amounts of metal species (i.e. in the parts per billion range).

In all cases, the treated effluent passes through multi-media filtration units prior to discharge. The five media layers prevent the possibility of losing any stray particles that might become entrained at high flow rates. After leaving the filtration units, the water passes through a sampling station. This clarified effluent may be discharged from the plant or stored in clean water storage tanks for additional treatment, recycling and re-use, depending on the demand for fresh make-up water from NewStream’s on-site customers.

Using a 24-hour composite, flow-weighted sampling device, the plant's effluent is sampled twice per week and analyzed for compliance with state and local pretreatment standards. Since commencing advanced wastewater treatment operations, the plant has consistently maintained compliance with all increasingly stringent permit discharge limits.

Instrumentation and Controls

All of the processes described above are automatically controlled by a centralized programmable logic controller (PLC). Information from each of 1500 data points is updated approximately every 45 milliseconds. Alarm points in tanks notify operators whenever manual intervention is necessary. Similarly, the automatic controller continuously monitors the effluent discharge for pH and turbidity — the two primary indicators that the treatment process is under control. In the event an upset is detected, the controller automatically diverts the flow back to the equalization/holding tanks. The wastewater treatment plant can continue operating in this manner for up to 48 hours without the need to shutdown manufacturing. In the meantime, the upset can usually be corrected. This fail safe system ensures that NewStream maintains the highest standard of compliance and process reliability.

The following downloadable materials are intended to provide generators and transporters with all the necessary information and paperwork for delivering and offloading wastewater at the NewStream facility.