06-096 C.M.R. ch. 584, § 5

The following assumptions have been used to determine the statewide criteria contained in Appendix A of this rule.

A. Form of metals. All metals criteria must be considered as total metal.

NOTE: Persons may request that the Department express criteria for metals as the dissolved form by submitting the appropriate information to allow recalculation of relative toxicity using conversion factors and translator procedures published by EPA: "The Metals Translator: Guidance for Calculating a Total Recoverable Permit Limit from a Dissolved Criterion", EPA 823-B-96-007, USEPA, Office of Water, Washington, DC, June 1996.

B. Ambient water physical characteristics. Fresh water quality must be calculated using a pH of 7.0, a temperature of 25 degrees Celsius, and a hardness of 20 mg/L. Marine water quality must be calculated using a pH of 8.0, a temperature of 20 degrees Celsius, and a salinity of 30 parts per thousand. Estuarine water quality must be calculated using a pH of 8.0, a temperature of 20 degrees Celsius and a salinity of 20 parts per thousand.

NOTE: These characteristics, however, may vary depending on the location of the discharge. The relative criteria for a pollutant subject to these considerations may be recalculated in any given licensing proceeding using the actual local ambient physical water characteristics. See Chapter 530.

C. Human health assumptions. In accordance with Human Health Ambient Water Quality Criteria: 2015 Update. EPA 820-F-15-001 (see Table I Footnote qq for a list of pollutants that were not included in this update due to ongoing research), human health criteria are determined assuming consumption of 2.4 Liters of water by a person weighing 80 kg, and a fish consumption rate of 32.4 grams per day. Notwithstanding the above, when calculating human health criteria for inorganic arsenic (which is governed by 38 M.R.S. §420(2)(J) ), the Department shall utilize a state-wide fish consumption rate of 138 grams per day. It is also noted that inorganic arsenic was not included in the 2015 EPA Human Health Ambient Water Quality Criteria document and therefore its criteria is calculated using 2 Liters of water and 70 kg for drinking water intake and body weight, respectively.

In waters subject to a designated use of sustenance fishing, human health criteria will be determined assuming consumption of 2.4 Liters of water by a person weighing 80 kg, and a fish consumption rate of 200 grams per day, except for those parameters that did not change with EPA's criteria recommendations referenced in EPA 820-F-15-001 for which the human health criteria will be determined assuming consumption of 2 Liters of water by a person weighing 70 kg, a fish consumption rate of 200 grams per day, and a cancer risk level of one in 1,000,000 (except for the cancer risk level for inorganic arsenic, which is governed by 38 M.R.S. §420(2)(J) ). Waters subject to a designated use of sustenance fishing are specified under 38 M.R.S. §465-A(1)(D), 38 M.R.S. §467(7)(A)(B)(D) 38 M.R.S. §467(13), 38 M.R.S. §467(15)(C), 38 M.R.S. §467(15)(A)(E)(F) 38 M.R.S. §468(8), 38 M.R.S. §469(7).

Notes

06-096 C.M.R. ch. 584, § 5