Section 6-121. Purchase of low-emission motor vehicles

a. As used in this
  section, the terms "as defined" and "as specified" shall mean as defined
  and as specified from time to time in the relevant  regulations  of  the
  administrator of the United States environmental protection agency.
    b.  As  used  in  this  section, the term "low-emission motor vehicle"
  shall mean a self-propelling light duty vehicle,  as  defined  which  is
  certified in accordance with the terms of subdivision d of this section.
    c.  Low-emission motor vehicles which meet the standards prescribed by
  subdivision e of this section, and which have  been  determined  by  the
  department of citywide administrative services to be suitable for use as
  a  substitute for a class or model of motor vehicles presently in use by
  the city of New York, shall be purchased by the city for use by the city
  government in lieu of other vehicles, provided that the commissioner  of
  citywide   administrative  services  shall  first  determine  that  such
  low-emission motor vehicles have procurement and maintenance  costs  not
  substantially greater than those of the class or model of motor vehicles
  for which they are to be substituted.
    d.  The  commissioner  of  environmental protection of the city of New
  York shall, upon request of the commissioner of citywide  administrative
  services,  and  after  such  tests  as  he  or she may deem appropriate,
  certify as a low-emission motor vehicle any particular class or model of
  motor vehicles that:
    1. meets either  (i)  the  hydrocarbon  and  carbon  monoxide  exhaust
  emission  standards  as  defined  and  as specified for nineteen hundred
  seventy-five model year vehicles and  the  oxides  of  nitrogen  exhaust
  emission standard as defined and as specified for the then current model
  year or (ii) the oxides of nitrogen exhaust emission standard as defined
  and  as  specified  for nineteen hundred seventy-six model year vehicles
  and the hydrocarbon and carbon monoxide exhaust  emission  standards  as
  defined and as specified for the then current model year; and
    2.  meets  the crankcase emission standard as defined and as specified
  and the fuel evaporative emission standard as defined and as  specified;
  and
    3.  will not emit an air contaminant not emitted by the class or model
  of motor vehicle presently in use in the city of  New  York  unless  the
  commissioner  of  environmental  protection  determines  that  such  air
  contaminant will not cause significant detriment to the health,  safety,
  welfare or comfort of any person, or injury to plant and animal life, or
  damage to property or business.
    4.  After  conducting  such  tests  the  commissioner of environmental
  protection shall advise  the  commissioner  of  citywide  administrative
  services  whether  such  class  or  model  of motor vehicles has been so
  certified. Any such certification shall be valid until the  end  of  the
  then  current  model  year  unless sooner revoked by the commissioner of
  environmental protection.
    e. The commissioner of environmental protection of  the  city  of  New
  York  shall, upon request of the commissioner of citywide administrative
  services, and after such tests as he or she may deem appropriate, advise
  the commissioner of citywide administrative services, as to any class or
  model of low-emission motor vehicle, with respect to:
    (1) the safety of the vehicle;
    (2) its performance characteristics;
    (3) its reliability potential; and
    (4) its fuel availability.