N.J. Admin. Code § 7:26E-3.8

Current through Register Vol. 56, No. 21, November 4, 2024

Section 7:26E-3.8 - Site investigation-natural background investigation of soil and ground water

(a) If during the site investigation, any contaminant that may be naturally occurring is found in soil at any area of concern in excess of a soil remediation standard, then the person responsible for conducting the remediation may investigate the extent to which the concentration of the contaminant in soil may be due to natural background. This investigation shall be conducted by:

1. Collecting and analyzing a sufficient number of samples in appropriate locations of similar soil type on or near the site that have not been impacted by current or historical on-site or off-site activities to adequately determine that the concentration of the contaminant in the soil may be due to natural background;

2. Demonstrating that the distribution of the contaminant in the soil does not follow a concentration gradient indicative of a discharge; and

3. Demonstrating that the concentration of the contaminant in the soil is within ranges reported in appropriate references for soil background levels for New Jersey, if available.

(b) In lieu of conducting a natural background investigation of soil pursuant to (a) above, the person responsible for conducting the remediation may use a previously conducted natural background determination to establish natural background soil concentration provided:

1. The prior natural background determination was conducted consistent with (a) above; and

2. The prior natural background determination was conducted at a location near enough to the site such that it is appropriate to use the previous study for this purpose.

(c) If during the site investigation, a contaminant is found in ground water in excess of the ground water remediation standard, then the person responsible for conducting the remediation may investigate the extent to which the concentration of the contaminant in ground water may be due to natural background. This investigation shall be conducted by:

1. Collecting and analyzing a sufficient number of samples in appropriate locations, both horizontally and vertically, on or near the site, that have not been impacted by current or historical on-site or off-site activities to adequately determine the concentration of the contaminant in the ground water is due to natural background;

2. Demonstrating the distribution of the contaminant in the ground water does not follow a concentration gradient indicative of a discharge; and

3. Demonstrating the concentration of the contaminant in ground water is within ranges reported in appropriate references for ground water background levels for New Jersey, if available.

(d) In lieu of conducting a natural background investigation of ground water pursuant to (c) above, the person responsible for conducting the remediation may use a previously conducted natural background determination to establish natural background ground water concentration provided:

1. The prior natural background determination was conducted in accordance with (c) above; and

2. The prior natural background determination was conducted at a location near the site such that it is appropriate to use the previous study for this purpose.

(e) To the extent that the person responsible for conducting the remediation concludes the presence of a contaminant in soil or ground water is due to natural background conditions, then no further remediation is necessary.

N.J. Admin. Code § 7:26E-3.8