Idaho § 39-6805 - STANDARDS FOR CONTAMINANT MANAGEMENT

§ 39-6805. STANDARDS FOR CONTAMINANT MANAGEMENT

(1) Except as otherwise provided in this chapter, contaminant management is required on all properties within the institutional controls administrative areas of OU-1, OU-2, and OU-3, including properties that have been remediated; properties tested and scheduled for remediation; properties not yet tested; properties with testing of deep soils (below eighteen (18) inches) by the applicant where a project may result in deep excavations; and properties with replacement and repair of remediation barriers in accordance with the remedial design report or other management activities designated for that geographic location or specific property.

(2) As necessary to protect public health and the environment, the department may impose contaminant management requirements, other than barrier installations, on projects where:

(a) For OU-1 and OU-2, soils exhibit lead concentrations in excess of three hundred fifty (350) parts per million (ppm) lead, particularly where a property has been remediated with either six (6) or twelve (12) inches of clean fill but contaminants in the three hundred fifty (350) to one thousand (1,000) ppm lead range remain below the six (6) or twelve (12) inch depth and those contaminants may be disturbed by a large or small project;

(b) For OU-1 and OU-2, any large or small project or building renovation involves the breaching or disturbance of a barrier or the disturbance or migration of contaminants exceeds one thousand (1,000) ppm lead; and

(c) For OU-3, properties testing below action levels in the top eighteen (18) inches where large or small projects may disturb contaminants below eighteen (18) inches are in excess of one thousand (1,000) ppm lead or one hundred (100) ppm arsenic.

(3) Developed recreation areas with surface soil containing lead concentrations greater than seven hundred (700) ppm lead and one hundred (100) ppm arsenic shall be capped pursuant to the applicable remedial design report or other management activities designated for that geographic location.

(4) Agricultural and undeveloped land within the institutional controls administrative area are exempt, unless excavation and grading activities such as soil transport off-site or development by the owner or his agents on these lands is likely to result in the release or migration of contaminants from these lands to adjacent nonagricultural or undeveloped areas.

(5) All barriers existing or constructed after the effective date of this chapter shall be maintained and protected to construction specifications as directed by the department. Materials used for barriers will be sampled for contaminants to ensure:

(a) For OU-1 and OU-2, that they have no earthen materials containing, on average, more than one hundred (100) ppm of lead or arsenic, nor more than five (5) ppm of cadmium, with no individual sample containing more than one hundred fifty (150) ppm of lead; and

(b) For OU-3, that soil and crushed aggregate/gravel imported for barrier material shall contain less than one hundred (100) ppm lead, thirty-five (35) ppm arsenic, and five (5) ppm cadmium based on average of backfill sampling results. No single sample of replacement materials may exceed one hundred fifty (150) ppm lead or forty-five (45) ppm arsenic.

(6) No new PUD or subdivision will be developed without contaminant management on any portion of the property that exceeds the following contaminant concentrations:

(a) For OU-1 and OU-2, average of three hundred fifty (350) ppm lead or a single lot exceeds one thousand (1,000) ppm lead; and

(b) For OU-3, one thousand (1,000) ppm lead or one hundred (100) ppm arsenic.

(7) No person may conduct, except in accordance with this chapter, any activity within the institutional controls administrative area that breaches a barrier, may breach a barrier, or disturbs the same or otherwise results in a threat to public health or the environment from the migration of contaminants through tracking on tires or vehicles, visible airborne dust, excavation, transport, disposal, renovation, demolition, or run-on or run-off from stormwater or in any other manner on properties tested and requiring remediation and on properties not yet tested within the institutional controls administrative area.

(8) Barriers are required as necessary to attain the standards described in this chapter. Construction and maintenance criteria for barriers are specified in the remedial design report designated for each applicable geographic location and are available through the department upon request.

[39-6805, added 2023, ch. 73, sec. 1, p. 245.]