437.10—Applicability.
        
        (a) 
         Except as provided in  § 437.1(b), (c), or (d) or in paragraph (b) of this section, this subpart applies to that portion of the discharge of wastewater from a CWT facility that results from the treatment of, or recovery of metals from, both metal-bearing wastes received from off-site and other CWT wastewater associated with the treatment of, or recovery of metal-bearing wastes.
    
    
        
        (b) 
         In order to ensure appropriate treatment rather than dilution of dissimilar wastes, an NPDES permit writer or control authority may require a new source or an existing facility subject to this subpart to achieve alternative effluent limitations and standards as defined in  § 437.2(b) in the following circumstances:
    
    
        
        (1) 
         The facility receives, on a continuing basis, flows of process wastewater from five or fewer facilities subject to 40 CFR Subchapter N limitations and standards; and
    
    
        
        (2) 
         The process wastewater flows received for treatment at the facility have relatively consistent pollutant profiles.
    
    
        
        (a) 
         Except as provided in  § 437.1(b), (c), or (d) or in paragraph (b) of this section, this subpart applies to that portion of the discharge of wastewater from a CWT facility that results from the treatment of, or recovery of metals from, both metal-bearing wastes received from off-site and other CWT wastewater associated with the treatment of, or recovery of metal-bearing wastes.
    
    
        
        (b) 
         In order to ensure appropriate treatment rather than dilution of dissimilar wastes, an NPDES permit writer or control authority may require a new source or an existing facility subject to this subpart to achieve alternative effluent limitations and standards as defined in  § 437.2(b) in the following circumstances:
    
    
        
        (1) 
         The facility receives, on a continuing basis, flows of process wastewater from five or fewer facilities subject to 40 CFR subchapter N limitations and standards; and
    
    
        
        (2) 
         The process wastewater flows received for treatment at the facility have relatively consistent pollutant profiles.