N.Y. Comp. Codes R. & Regs. tit. 6, § 702.15 – Derivation of guidance values.

(a) For those substances that do not have an applicable Health (Water Source) standard in section 703.5 of this Title and that the department determines may pose a threat to human health if discharged to the waters of the State, a guidance value may be derived and shall be the most stringent of the following:
1. (1) the values derived by applying the procedures from sections 702.3 through 702.7 of this Part;
2. (2) a “general organic guidance value” of 50 ug/L for an individual organic substance. This paragraph does not apply if adequate and sufficient data are available to justify values greater than 50 ug/L using procedures from both sections 702.4 and 702.5 of this Part. The general organic guidance value applies only to those substances specified by the department; or
3. (3) a "specific organic mixture guidance value" of 100 ug/L for a commercially available mixture of individual organic substances. This paragraph does not apply if adequate and sufficient data are available to justify values greater than 100 ug/L using procedures from both sections 702.4 and 702.5 of this Part. The derivation of this value for any specified mixture does not preclude the existence or derivation of a Health (Water Source) standard or guidance value for any individual organic substance in the mixture. The specific organic mixture guidance value applies only to those mixtures specified by the department.
(b) For those substances that do not have an applicable Health (Fish Consumption) standard in section 703.5 of this Title and that the department determines may pose a threat to human health if discharged to the waters of the State, a guidance value may be derived by applying the procedures from section 702.8 of this Part.
1. (1) For those substances that do not have an applicable Aquatic (Chronic) standard in section 703.5 of this Title and that the department determines may pose a threat to aquatic life or the environment if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.9 of this Part.
2. (2) For those substances that have an identified applicable Aquatic (Chronic) standard in section 703.5 of this Title, a guidance value shall be substituted where the procedures in section 702.9 of this Part yield a more stringent value. Remarks in Table 1 of section 703.5(f) of this Title identify the standards to which this paragraph applies. This paragraph applies only to the waters of the Great Lakes System.
  (d)
3. (1) For those substances that do not have an applicable Aquatic (Acute) standard in section 703.5 of this Title and that the department determines may pose a threat to aquatic life or the environment if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.9 of this Part.
4. (2) For those substances that have an identified applicable Aquatic (Acute) standard in section 703.5 of this Title, a guidance value shall be substituted where the procedures in section 702.9 of this Part yield a more stringent value. Remarks in Table 1 of section 703.5(f) of this Title identify the standards to which this paragraph applies. This paragraph applies only to the waters of the Great Lakes System.
(c)
(e) For those substances that do not have an applicable Wildlife standard in section 703.5 of this Title and that the department determines may pose a threat to wildlife if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.13 of this Part.
(f) For those substances that do not have an applicable Aesthetic (Water Source) standard in section 703.5 of this Title and that the department determines may pose a threat to the aesthetic quality of sources of potable water if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.14 of this Part.
(g) For those substances that do not have an applicable Aesthetic (Food Source) standard in section 703.5 of this Title and that the department determines may pose a threat to the aesthetic quality of food for human consumption if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.14 of this Part.
(h) For those parameters that do not have an applicable Recreation standard in section 703.5 of this Title and that the department determines may pose a threat to the quality of the water for recreation if discharged to the waters of the State, a guidance value may be derived by applying the appropriate procedure from section 702.12 of this Part.