N.Y. Comp. Codes R. & Regs. tit. 6, § 637.4 – Employment of persons in environmental conservation programs.

(a) No agency shall hereafter employ individuals who perform the functions of environmental engineer, environmental scientist, environmental technician or environmental aide, as detailed in this Part, unless the proposed appointee shall have presented in advance to such authority satisfactory evidence from the department that the applicant possesses the qualifications established by sections 637.6 through 637.9 of this Part.

(b) Persons responsible for planning, directing and administering all environmental conservation programs and those responsible for engineering functions in environmental conservation agencies shall have the qualifications approved at the levels shown in the following table, depending upon population of jurisdiction:

TABLE Required Levels for Certain Functions

Population of jurisdiction agency	Required minimum level for individual responsible for planning, directing, and administering all environmental conservation programs	Minimum level required for individual responsible for all engineering functions in the agency
350,000 or greater	Principal environmental engineer or principal environmental scientist	Associate environmental engineer
Over 100,000 but less than 350,000	Associate environmental engineer or associate	Senior environmental engineerX
Less than 100,000	Senior environmental engineer or senior environmental scientist	Senior environmental engineer

(c) The provisions of sections 637.6 through 637.9 of this Part shall not interfere with the appointment of any person from a civil service list established prior to November 30, 1977, nor shall they interfere with the continued employment or advancement of an individual appointed from a civil service list prior to November 30, 1977 within a particular occupational series under the jurisdiction of these sections.
(d) The provisions of sections 637.6 through 637.9 of this Part shall not interfere with the appointment or employment of any individual by a local health department, providing that individual is qualified under appropriate regulations of the State Department of Health.