Author: John Wentz, P.E., Process Plus Director of Water/Wastewater Services
December 23, 2013
What are the objectives of your industrial wastewater treatment system? For most industrial applications, it is to provide a treated wastewater that meets the discharge requirements of the local municipality, with the lowest capital and operational costs. To be accomplished, the ultimate fate of your treated wastewater and residuals must be known; as well as the regulations under which the treatment, discharge and residuals management must be performed.
Most industrial wastewater pretreatment systems consist of separation and/or concentration based technologies rather than constituent destruction. As a result, two streams typically result from the treatment process, including treated wastewater and waste byproduct that may consist of sludge, scum and/or concentrate. The objectives for the fate of the wastewater after treatment need to be established in order for the appropriate treatment process(es) to be selected and placed in the proper sequence (Treatment Train). The Treatment Train is based on the constituents in the wastewater that require reduction/removal, constituents that can cause interference in the treatment process and the final fate of the treated wastewater. Wastewater treatment and residuals management objectives may include:
New wastewater treatment systems, upgrades and modifications to existing processes, chemicals used in the process, or changes in the volume treated can lead to environmental permit requirements. Typically these changes require a permit application to, and permit from the local POTW indicating that the treated wastewater will be acceptable in the quantity and quality as described in the application. Some states (Ohio for example) also require a state level Permit to Install (PTI) application. The PTI from the state cannot be issued without the local POTW approval. As a result, it is recommended that facilities considering new wastewater treatment or modifications to existing treatment systems establish communication early with local and state regulatory personnel to discuss plans while they are in the developmental stage. As each site has its own unique set of conditions, having the regulators involved earlier in the process helps them to understand the rationale behind the process and site conditions and will facilitate the environmental permitting process.
Wastewater
Direct discharge under National Pollutant Discharge Elimination System (NPDES) Permit (directly into a receiving stream)
Indirect discharge to a Publicly Owned Treatment Works (POTW)
Treatment for recovery/reuse opportunities
Consideration of chemicals used in the treatment process for resulting waste stream reuse opportunities
Residuals Management
Off-site transportation and disposal
– Expensive
– Long-term liability
Raw material or product recovery
Beneficial reuse
– May off-set costs associated with treatment
– May have positive impact on Sustainability initiatives
– Can be influenced by the chemicals used in the treatment process
New wastewater treatment systems, upgrades and modifications to existing processes, chemicals used in the process, or changes in the volume treated can lead to environmental permit requirements. Typically these changes require a permit application to, and permit from the local POTW indicating that the treated wastewater will be acceptable in the quantity and quality as described in the application. Some states (Ohio for example) also require a state level Permit to Install (PTI) application. The PTI from the state cannot be issued without the local POTW approval. As a result, it is recommended that facilities considering new wastewater treatment or modifications to existing treatment systems establish communication early with local and state regulatory personnel to discuss plans while they are in the developmental stage. As each site has its own unique set of conditions, having the regulators involved earlier in the process helps them to understand the rationale behind the process and site conditions and will facilitate the environmental permitting process.
