250 R.I. Code R. 250-RICR-140-30-1.9

Current through December 26, 2024

Section 250-RICR-140-30-1.9 - Risk Management

1.9.1 Remedial Objectives

A. The appropriate remedial objectives for all Hazardous Substances in all impacted media at a Contaminated-Site shall be consistent with this rule so as to manage the actual or potential risks to human health and the environment by ensuring that the following requirements are met:

1. The remedial objective for each carcinogenic substance does not exceed a 1 X 10^-6 excess lifetime cancer risk level and the cumulative excess lifetime cancer risk posed by the Contaminated-Site does not exceed 1 X 10^-5;

2. The remedial objective for each non-carcinogenic substance does not exceed a Hazard Index of 1 and the cumulative Hazard Index posed by the Contaminated-Site does not exceed 1 for any target organ;

3. The remedial objective will not significantly contribute to adverse effects to any Environmentally Sensitive Areas at or in the vicinity of the Contaminated-Site;

4. The remedial objective will be protective of the natural resources of the State, including but not limited to groundwater; and

5. The remedial objective shall address the requirements of §1.9.7 of this Part.

B. Specific requirements for the development and application of concentration-based soil and groundwater objectives are presented throughout the remainder of this section. Concentration-based soil and groundwater objectives may consider background conditions.

1.9.2Soil Objectives

A. Unless otherwise specified in these regulations, soil contaminated as a result of a Release of Hazardous Materials shall be remediated in a manner which meets the direct exposure and leachability criterion for each Hazardous Substance established in Tables 1 and 2, §§1.9.2(C)(2) and (3), 1.9.2(D) or 1.9.4 of this Part; or the background concentration of the Hazardous Substance as established by §1.9.6 of this Part. All soil objectives shall be consistent with §§1.9.1 and 1.9.2(B) of this Part.

B. General Requirements for Soil Objectives:

1. General Requirements for Direct Exposure Criteria:

a. With respect to any Hazardous Substance in soil at a Contaminated-Site, the Director may approve the application of a direct exposure criterion provided it is demonstrated to the satisfaction of the Director that the application of such direct exposure criterion at the Contaminated-Site will be protective of current and reasonably foreseeable future human exposure.

b. Regardless of the method employed for determining the direct exposure criterion, the residential direct exposure criterion shall be applied throughout the vadose zone for each Hazardous Substance in soil, except as otherwise provided in this rule.

c. The industrial/commercial direct exposure criterion may be applied to a depth of at least 2 feet below ground surface for each Hazardous Substance in soil if all of the following conditions are met:

(1) The Contaminated-Site is currently limited to Industrial/Commercial Activity;

(2) Access to the property containing the Contaminated-Site is limited to individuals working at or temporarily visiting the subject parcel;

(3) The current and reasonably foreseeable future human exposure to soils at the Contaminated-Site is not expected to occur beyond a depth of 2 feet below ground surface; and

(4) An environmental land usage restriction consistent with §1.9.9 of this Part is in effect with respect to the property, or to the portion of the property containing the Contaminated-Site; such an environmental land usage restriction shall ensure that the property or restricted portion thereof is not used for any Residential Activity in the future and that any future use of the property or restricted portion thereof is limited to industrial/commercial activity.

2. General Requirements for Leachability Criteria:

a. With respect to any Hazardous Substance in soil at a Contaminated-Site, the Director may approve a leachability criterion provided it is demonstrated to the satisfaction of the Director that the application of such leachability criterion at the Contaminated-Site is protective of the following:

(1) The actual and potential uses of the groundwater at the Contaminated-Site by ensuring that, at a minimum, the leachability criterion will not contribute to an exceedance of the applicable groundwater objective for the Hazardous Substance as described in §1.9.3 of this Part; and

(2) Surface water at or in the vicinity of the Contaminated-Site from potential migration of groundwater.

b. Regardless of the method employed for determining the leachability criterion, the GA leachability criterion shall be applied throughout the vadose zone for each Hazardous Substance in soil, except as otherwise provided in this rule.

c. The GB leachability criterion may be applied throughout the vadose zone for each substance in soil if both of the following conditions are met:

(1) The GB groundwater objective is applicable to the groundwater of concern underlying and downgradient of the Contaminated-Site in accordance with §1.9.3 of this Part; and

(2) The application of the GB leachability criterion will not contribute to actual or potential impacts to surface water and/or sediments as described in the policies and regulations of the Office of Water Resources.

3. Method Requirements for Soil Objectives:

a. For each of the Hazardous Substances at a Contaminated-Site, the Director shall approve the application of a Method 1 Soil Objective established in §1.9.2(C) of this Part provided that the application of the Method 1 Soil Objective is consistent with §§1.9.1 and 1.9.2(A) of this Part and the objective is specified in Tables 1 and 2, §§1.9.2(C)(2) and (3) of this Part, as appropriate.

b. If no Method 1 Soil Objective has been promulgated for one or more Hazardous Substances in soil at a Contaminated-Site, then the following options are available:

(1) Method 2 may be used to develop soil objectives for the Contaminated-Site as described in §1.9.2(D) of this Part. Method 2 Soil Objectives may be used alone or in combination with other Method 1 Soil Objectives. A combined Method 1 and Method 2 approach shall be considered to result in Method 2 Soil Objectives; or

(2) Method 3 may be used to develop soil objectives for the Contaminated-Site as described in §1.9.4 of this Part.

c. If a Method 1 Soil Objective has been promulgated for one or more Hazardous Substances in soil at a Contaminated-Site, then the following options are available:

(1) The Performing Party may only propose Method 2 to develop leachability criteria, as described in §1.9.2(D) of this Part. Method 2 Leachability Criteria may be used alone or in combination with other Method 1 Leachability Criteria. A combined Method 1 and Method 2 approach shall be considered to result in Method 2 Soil Objectives; or

(2) Method 3 may be used to develop soil objectives for the Contaminated-Site as described in §1.9.4 of this Part.

d. For Hazardous Substances in soil that are determined by either the Department or the Performing Party to have a potential to significantly contribute to adverse effects to any Environmentally Sensitive Area at or in the vicinity of the Contaminated-Site, a Method 3 Ecological Risk Assessment shall be performed in accordance with §1.9.5 of this Part.

4. Soil Objectives for Total Petroleum Hydrocarbons (TPH):

a. Although not a single Hazardous Substance, TPH can be useful as an indicator of potential adverse impacts to human health from a Release of Hazardous Materials. TPH Soil Objectives shall be applied to a Contaminated-Site for which jurisdiction has been established through the discovery of a Release as described in § 1.6 of this Part. The Department will utilize these objectives for non-virgin petroleum/weathered petroleum situations as they occur at Contaminated-Sites.

b. Accordingly, the Department shall require that soil objectives for TPH as described in this Rule be applied to a Contaminated-Site in conjunction with soil objectives for the Hazardous Substances established pursuant to this section. The Director shall approve the application of the functional equivalent of a direct exposure criterion and leachability criterion for TPH provided that the application of the criteria is consistent with §§1.9.1 and 1.9.2(A) of this Part. The Performing Party shall apply the soil objectives for TPH described below.

(1) The following shall be considered the Method 1 Direct Exposure Criteria for TPH, subject to the provided requirements:

(AA) The Method 1 Residential TPH Direct Exposure Criterion shall be 500 ppm; or

(BB) The Method 1 Residential TPH Direct Exposure Criterion may be 1000 ppm contingent upon field-verification by Department Personnel to ensure that short-term risks are managed appropriately prior to approval as a final remedial objective; and The Method 1 Industrial/Commercial TPH Direct Exposure Criterion shall be 2500 ppm.

(2) The following shall be considered the Method 1 Leachability Criteria for TPH, subject to the provided requirements:

(AA) The Method 1 GA TPH Leachability Criterion shall be 500 ppm; or

(BB) The Method 1 GA TPH Leachability Criterion may be 1000 ppm and may be field-verified at the discretion of the Department to ensure that short-term risks are managed appropriately prior to approval as a final remedial objective; and

(CC) The Method 1 GB TPH Leachability criterion shall be 2500 ppm.

c. For clarity, any reference to concentrations of Hazardous Substances in the following rules shall be considered by the Department to be in addition to the appropriate concentrations of TPH as described herein: §§1.9.2, 1.9.4, 1.9.6, 1.9.8(A), 1.9.9 and 1.9.10 of this Part.

C. Method 1 Soil Objectives:

1. Unless otherwise prohibited by the Director, the Method 1 Soil Objectives specified in Tables 1 and 2, §§1.9.2(C)(2) and (3) of this Part may be applied to a Contaminated-Site provided that the conditions set forth in §§1.9.1 and 1.9.2(A) of this Part are met.

a. Method 1 Direct Exposure Criteria: The Method 1 Direct Exposure Criteria are listed in Table 1, §1.9.2(C)(2) of this Part.

b. Method 1 Leachability Criteria:

(1) The Method 1 Leachability Criteria are listed in Table 2, §1.9.2(C)(3) of this Part.

(2) With respect to the Method 1 Leachability Criteria for inorganic Hazardous Substances, the Performing Party shall conduct a laboratory test that demonstrates that the inorganic Hazardous Substance will not leach to groundwater at levels which exceed the applicable groundwater objective for the inorganic Hazardous Substance. Accordingly, the resulting leachate concentration shall not exceed the leachability criteria for the associated inorganic Hazardous Substance listed in Table 2, §1.9.2(C) (3) of this Part.

(3) The Performing Party may perform the Synthetic Precipitation Leaching Procedure (SPLP; EPA Method 1312), § 1.16(E) of this Part, the Toxicity Characteristic Leaching Procedure (TCLP; EPA Method 1311), § 1.16(F) of this Part, or other procedures pre-approved by the Department to estimate potential leaching of inorganic Hazardous Substances at the Contaminated-Site.

2. Table 1

DIRECT EXPOSURE CRITERIA
Substance	Residential (mg/kg)	Industrial/Commercial (mg/kg)
Volatile Organics
Acetone	7,800	10,000
Benzene	2.5	200
Bromodichloromethane	10	92
Bromoform	81	720
Bromomethane	0.8	2900
Carbon tetrachloride	1.5	44
Chlorobenzene	210	10,000
Chloroform	1.2	940
Dibromochloromethane	7.6	68
1,2- Dibromo-3-chloropropane (DBCP)	0.5	4.1
1,1-Dichloroethane	920	10,000
1, 2-Dichloroethane	0.9	63
1,1-Dichloroethene	0.2	9.5
cis-1, 2-Dichloroethene	630	10,000
Trans-1, 2-Dichloroethene	1,100	10,000
1, 2-Dichloropropane	1.9	84
Ethylbenzene	71	10,000
Ethylene dibromide (EDB)	0.01	0.07
Isopropyl benzene	27	10,000
Methyl ethyl ketone	10,000	10,000
Methyl isobutyl ketone	1200	10,000
Methyl tertiary-butyl ether (MTBE)	390	10,000
Methylene chloride	45	760
Styrene	13	190
1,1,1,2-Tetrachloroethane	2.2	220
1,1, 2, 2-Tetrachloroethane	1.3	29
Tetrachloroethene	12	110
Toluene	190	10,000
1,1,1-Trichloroethane	540	10,000
1, 1, 2-Trichloroethane	3.6	100
Trichloroethene	13	520
Vinyl chloride	0.02	3.0
Xylenes (Total)	110	10,000
Semivolatiles
Acenaphthene	43	10,000
Acenaphthylene	23	10,000
Anthracene	35	10,000
Benzo(a)anthracene	0.9	7.8
Benzo(a)pyrenea	0.4	0.8
Benzo(b)fluoranthene	0.9	7.8
Benzo(g,h,i)perylene	0.8	10,000
Benzo(k)fluoranthene	0.9	78
1,1-Biphenyl	0.8	10,000
Bis(2-ethylhexyl)phthalate	46	410
Bis(2-chloroethyl)ether	0.6	5.2
Bis(2-chloroisopropyl)ether	9.1	82
4-Chloroaniline (p-)	310	8200
2-Chlorophenol	50	10,000
Chrysene	0.4	780
Dibenzo(a,h)anthracenea	0.4	0.8
1,2-Dichlorobenzene (o-DCB)	510	10,000
1,3-Dichlorobenzene (m-DCB)	430	10,000
1,4-Dichlorobenzene (p-DCB)	27	240
3,3-Dichlorobenzidine	1.4	13
2,4-Dichlorophenol	30	6,100
2,4-Dimethyl phenol	1,400	10,000
Diethyl phthalate	340	10,000
Dimethyl phthalate	1,900	10,000
2,4-Dinitrophenol	160	4,100
2,4-Dinitrotoluene	0.9	8.4
Fluoranthene	20	10,000
Fluorene	28	10,000
Hexachlorobenzene	0.4	3.6
Hexachlorobutadiene	8.2	73
Hexachloroethane	46	410
Indeno(1,2,3-cd)pyrene	0.9	7.8
2-Methyl naphthalene	123	10,000
Naphthalene	54	10,000
Pentachlorophenol	5.3	48
Phenanthrene	40	10,000
Phenol	6,000	10,000
Pyrene	13	10,000
1,2,4-Trichlorobenzene	96	10,000
2,4,5-Trichlorophenol	330	10,000
2,4,6-Trichlorophenol	58	520
Pesticides/PCBs
Chlordane	0.5	4.4
Dieldrin	0.04	0.4
Polychlorinated biphenyls (PCBs)b	10	10
Inorganics
Antimony	10	820
Arsenicc	7.0	7.0
Barium	5,500	10,000
Berylliumc	1.5	1.5
Cadmium	39	1,000
Chromium III (Trivalent)	1,400	10,000
Chromium VI (Hexavalent)	390	10,000
Copper	3,100	10,000
Cyanide	200	10,000
Leadd	150	500
Manganese	390	10,000
Mercury	23	610
Nickel	1,000	10,000
Selenium	390	10,000
Silver	200	10,000
Thallium	5.5	140
Vanadium	550	10,000
Zinc	6,000	10,000
a Estimated quantitation limits.
b Direct Exposure Criteria for PCBs consistent with the Toxic Substance Control Act (TSCA)
c Background Levels of Priority Pollutant Metals In Rhode Island Soils, T. O'Connor, RIDEM - Standard set @ statistical 95% upper confidence limit of natural background data across State. For arsenic, see also § 1.13 of this Part.
d Direct Exposure Criteria for Lead consistent with the Rhode Island Department of Health Lead Poisoning Prevention regulations, 216-RICR- 50-15-3

3. Table 2

LEACHABILITY CRITERIA
Substance	GA Leachability (mg/kg except as otherwise noted)	GB Leachability (mg/kg)
Volatile Organics
Benzene	0.2	4.3
LEACHABILITY CRITERIA
Carbon tetrachloride	0.4	5.0
Chlorobenzene	3.2	100
1,2-Dichloroethane	0.1	2.3
1,1-Dichloroethene	0.7	0.7
cis-1,2-Dichloroethene	1.7	60
Trans-1,2-Dichloroethene	3.3	92
1,2-Dichloropropane	0.1	70
Ethylbenzene	27	62
Ethylene dibromide (EDB)	5E-04	-
Methyl-tertiary-butyl-ether (MTBE)	0.9	100
Styrene	2.9	64
Tetrachloroethene	0.1	4.2
Toluene	32	54
1,1,1-Trichloroethane	11	160
1,1,2-Trichloroethane	0.1	-
Trichloroethene	0.2	20
Vinyl chloride	0.3	-
Xylenes	540	-
LEACHABILITY CRITERIA
Semivolatiles
Benzo(a)pyrene	240	-
Dichlorobenzene (all isomers)	41	-
Diethylhexyl phthalate	120	-
Napthalene	0.8	-
Pentachlorophenol	7.1	-
1,2,4-Trichlorobenzene	140	-
Pesticides/PCBs
Chlordane	1.4	-
Polychlorinated biphenyls (PCBs)a	10.0	10.0
Inorganics
Antimony (TCLP/SPLP)	0.05	-
Barium (TCLP/SPLP)	23
Beryllium (TCLP/SPLP)	0.03
Cadmium (TCLP/SPLP)	0.03	-
Chromium (TCLP/SPLP)	1.1	-
Cyanide (TCLP/SPLP)	2.4	-
Lead (TCLP/SPLP)	0.04	-
LEACHABILITY CRITERIA
Mercury (TCLP/SPLP)	0.02	-
Nickel (TCLP/SPLP)	1	-
Selenium (TCLP/SPLP)	0.6	-
Thallium (TCLP/SPLP)	0.005	-
"-" No Method 1 GB Leachability Criteria promulgated
a Leachability criteria for PCBs consistent with the Toxic Substance Control Act (TSCA)

D. Method 2 Soil Objectives

1. Method 2 allows for the consideration of limited site-specific information to modify Method 1 Soil Objectives or to calculate soil objectives for Hazardous Substances not listed in Table 1 or 2, §§1.9.2(C)(2) or (3) of this Part. For the purposes of these regulations, a Method 2 Soil Objective shall refer to any soil objective which addresses site-specific conditions established pursuant to this Part and in accordance with the appropriate information presented in §§ 1.17 and 1.18 of this Part.

2. The Department reserves the right to require the development of Method 2 Soil Objectives based on complicated conditions at a Contaminated-Site, including, but not limited to potential adverse impacts to adjacent surface water bodies or other potential impacts to human health and/or the environment.

3. Method 2 Soil Objectives shall be consistent with §§1.9.1, and 1.9.2(B) of this Part and shall meet all of the following conditions in §§1.9.2(D)(3)(a) through (d) of this Part listed below:

a. Direct Exposure Criteria shall only be developed under Method 2 for those Hazardous Substances which are not specified under Method 1 in Table 1, §1.9.2(C)(2) of this Part. Method 2 Direct Exposure Criteria shall be developed using the default assumptions provided in § 1.17 of this Part. The chemical-specific inputs used to develop the Method 2 Direct Exposure Criteria are subject to the approval of the Director for each proposed application;

b. Method 2 Soil Objectives shall be developed for Hazardous Substances on the basis of the following assumptions and procedures:

(1) Based upon non-cancer health risk, a concentration of the Hazardous Substance associated with 100% of the Reference Dose shall be calculated consistent with residential or Industrial/Commercial Activity as appropriate pursuant to §1.9.2(B)(1) of this Part using the algorithm specific to the ingestion pathway provided in § 1.17 of this Part. For a Contaminated-Site which impacts one or more properties utilized for any Residential Activity, a concentration of the Hazardous Substance associated with acute ingestion and the inhalation pathway shall also be calculated using the appropriate algorithms in § 1.17 of this Part;

(2) A concentration of the Hazardous Substance associated with an Excess Lifetime Cancer Risk equal to no more than one excess cancer case in one million people exposed to the Hazardous Substance shall be calculated consistent with residential or Industrial/Commercial Activity as appropriate pursuant to §1.9.2(B)(1) of this Part using the algorithm specific to the ingestion pathway provided in § 1.17 of this Part. For a Contaminated-Site which impacts one or more properties utilized for any Residential Activity, a concentration of the Hazardous Substance associated with the inhalation pathway shall be calculated using the appropriate algorithm in § 1.17 of this Part;

(3) For a Contaminated-Site impacting one or more properties utilized for any Residential Activity, the soil saturation concentration (C_sat) of the Hazardous Substance above which pure liquid-phase contaminant is expected in the vadose zone shall be calculated using the equation provided in § 1.17 of this Part and appropriate chemical-specific and/or soil specific data collected from the Contaminated-Site;

(4) For each concentration of Hazardous Substance calculated consistent with residential or Industrial/Commercial Activity as appropriate pursuant to §1.9.2(B)(1) of this Part, the lowest non-zero concentration estimated in §§1.9.2(D)(3)(b) ((1)) through ((3)) of this Part shall be the Method 2 Direct Exposure Criterion for the Hazardous Substance;

(5) Considering the groundwater classification at the Contaminated-Site, the Method 2 Leachability Criterion shall be developed utilizing a Department-approved leaching model or test method which demonstrates that the concentrations of the Hazardous Substance in soil at a Contaminated-Site now and in the reasonably foreseeable future will result in compliance with all applicable groundwater objectives for that Hazardous Substance. Therefore, the Department shall approve the target groundwater objective for each Hazardous Substance established in accordance with this Section prior to the development of the associated Method 2 Leachability Criterion.

(6) Specifically, Method 2 Leachability Criteria shall be determined by performing the following:

(AA) Method 2 Leachability Criteria for Organic Hazardous Substances: The Performing Party may provide a leaching-to-groundwater compliance demonstration with a Department-approved fate and transport model such as that discussed in § 1.18 of this Part which incorporates site-specific information such as physical and chemical properties of the Hazardous Substances including, but not limited to toxicity and mobility, source quantity, subsurface hydrogeological conditions and net precipitation; and

(BB) Method 2 Leachability Criteria for Inorganic Hazardous Substances: The Performing Party shall conduct a laboratory test consistent with that described in §1.9.2(B)(2) of this Part. The Performing Party may develop a Method 2 Leachability Criterion for an inorganic Hazardous Substance by calculating a site-specific dilution/attenuation factor using the algorithm in §1.18.7 of this Part to be multiplied by the appropriate groundwater objective;

(7) A site-specific background concentration of the Hazardous Substance in soil may be calculated and considered for the Hazardous Substance pursuant to §1.9.6 of this Part; and

(8) The Practical Quantitation Limit (PQL) of the Hazardous Substance using an appropriate analytical method for quantifying the concentration of the chemical in soil may be calculated and considered;

c. If the development of a Method 2 Soil Objective results in a concentration of a Hazardous Substance which exceeds any Upper Concentration Limit as described in §1.9.7 of this Part, then the Department reserves the right to require that the modification be adjusted downward to a concentration which prevents the exceedance; and d. The development of Method 2 Soil Objectives shall be based upon information which is scientifically justified and completely documented with site data collected from the Contaminated-Site. At a minimum, Method 2 Soil Objective development shall be documented with sufficient information to allow the Director to evaluate the following factors:

(1) The appropriateness and validity of any chemical-specific and/or site-specific input parameters used;

(2) Whether the calculations were correctly performed;

(3) The potential for soils at the Contaminated-Site to pose a significant risk to human health and the environment after the proposed Method 2 Soil Objectives are applied to the Contaminated-Site as part of a Remedial Action; and

(4) Background levels for the applicable Hazardous Substances, if determined.

1.9.3Groundwater Objectives

A. Unless otherwise specified in these regulations or otherwise provided by the Director, groundwater contaminated as a result of a Release of Hazardous Materials located in a GA/GAA area shall be remediated to a concentration which meets the groundwater objective for each Hazardous Substance established in §1.9.3(F)(2) of this Part and specified in Table 3, §§1.9.3(F)(4) or 1.9.4 of this Part; the Department's "Groundwater Quality Rules," or the background concentration of the Hazardous Substance. Any Method 3 GA Groundwater Objective which deviates from the Method 1 GA Groundwater Objective shall meet the requirements of the Groundwater Quality Rules, Part 150-05-3 of this Title.

B. Groundwater contaminated as a result of a Release of Hazardous Materials located in a GB area shall be remediated to a concentration which meets the groundwater objective for each Hazardous Substance established in §1.9.3(F) (3) of this Part and specified in Table 4 §§1.9.3(F)(5), 1.9.3(G)(1) or 1.9.4 of this Part; or the background concentration of the Hazardous Substance.

C. All groundwater objectives shall be consistent with §§1.9.1 and 1.9.3(D) of this Part.

D. General Requirements for Groundwater Objectives:

1. General Requirements for GA Groundwater Objectives:

a. GA Groundwater Objectives may not be set at levels, except within an approved discharge zone or residual zone (as provided for in the Department's Groundwater Quality Rules, Part 150-05-3 of this Title) which will adversely affect the groundwater as a source of potable water or which will adversely affect other beneficial uses of groundwater, including but not to be limited to recreational, agricultural and industrial uses and the preservation of fish and wildlife habitat through the maintenance of surface water quality; and

b. GA Groundwater Objectives may not be set at levels which exceed or have reasonable potential to cause exceedance of surface water quality standards established by the Department's Water Quality Rules, Part 150-05-3 of this Title and amendments thereto.

2. General Requirements for GB Groundwater Objectives:

a. The GB Groundwater Objectives shall be applied in the restoration of the State's groundwater resources which are not for use as current or potential sources of drinking water. GB Groundwater Objectives shall be based on the potential for volatile organic compounds found or suspected in GB areas to volatilize from the groundwater and migrate to indoor air. These GB Groundwater Objectives are based on controlling the threat to human health from the inhalation of these Hazardous Substances.

b. The GB Groundwater Objectives shall be applied to the restoration of groundwater in GB Areas under the control of the Performing Party, provided that the Department determines that the following conditions apply to the contaminated groundwater:

(1) The extent and nature of the groundwater contamination does not pose a substantial likelihood of exceeding a surrounding GA Groundwater Objective;

(2) The extent and nature of the groundwater contamination does not pose a substantial likelihood of adversely affecting current uses of groundwater, surface water resources or surrounding properties as they exist at the time that the site investigation work is conducted (i.e., adverse off-site impacts are eliminated or effectively mitigated);

(3) The groundwater of concern is not located in a designated buffer zone around a licensed solid waste management facility and specific exceedances are acknowledged as part of the operating permit; and

(4) The groundwater of concern does not pose a significant threat to the classification and/or actual and potential uses of the surface water bodies in the vicinity of the Contaminated-Site consistent with the policies and regulations of the Office of Water Resources, or to human health and the environment.

E. Method Requirements for Groundwater Objectives:

1. Method Requirements for GA Groundwater Objectives

a. For each of the Hazardous Substances at a Contaminated-Site, the Director shall approve the application of a Method 1 GA Groundwater Objective established in §1.9.3(F)(2) of this Part provided that the application of the Method 1 GA Groundwater Objective is consistent with §§1.9.1 and 1.9.3(D) of this Part and the objective is specified in Table 3, §1.9.3(F)(4) of this Part.

b. The Performing Party may develop groundwater objectives under Method 3, as described in §1.9.4 of this Part. Groundwater objectives developed using Method 3 may be used alone or in combination with other Method 1 Groundwater Objectives. A combined Method 1 and Method 3 approach shall be considered to result in Method 3 GA Groundwater Objectives.

2. Method Requirements for GB Groundwater Objectives:

a. For each of the Hazardous Substances at the Contaminated-Site, the Director shall approve the application of a Method 1 GB Groundwater Objective established in §1.9.3(F)(3)(a) of this Part provided that the Method 1 GB Groundwater Objective is consistent with §1.9.1 of this Part (Remedial Objectives), §1.9.3(D) of this Part and the objective as specified in Table 4, §1.9.3(F)(5) of this Part.

b. The following options are also available to the Performing Party with respect to GB Groundwater Objective development

(1) Method 2 may be used to develop groundwater objectives for the Contaminated-Site as described in §1.9.3(G) of this Part (Method 2 GB Groundwater Objectives). Method 2 GB Groundwater Objectives may be used alone or in combination with Method 1 GB Groundwater Objectives. A combined Method 1 and Method 2 approach shall be considered to result in Method 2 GB Groundwater Objectives.

(2) Method 3 may be used to develop groundwater objectives for the Contaminated-Site as described in §1.9.4 of this Part; or

(3) The Method 1 GA Groundwater Objectives as specified in Table 3, §1.9.3(F)(4) of this Part may be used for those Hazardous Substances not included in Table 4, §1.9.3(F)(5) of this Part.

c. For Hazardous Substances in groundwater that are determined by either the Department or the Performing Party to significantly contribute to adverse effects to any Environmentally Sensitive Area at or in the vicinity of the Contaminated-Site, a Method 3 Ecological Risk Assessment shall be performed in accordance with §1.9.5 of this Part (Ecological Protection).

F. Method 1 Groundwater Objectives:

1. Unless otherwise prohibited by the Director, the Method 1 Groundwater Objectives may be applied to a Contaminated-Site provided that the conditions set forth in §1.9.1 of this Part (Remedial Objectives) and §1.9.3(D) of this Part (General Requirements for Groundwater Objectives).

2. Method 1 GA Groundwater Objectives:

Groundwater which is classified as a GA/GAA area is categorized as or presumed to be suitable for drinking water use without treatment, and is subject to the GA Groundwater Objectives listed in Table 3, §1.9.3(F)(4) of this Part, and the Department's Groundwater Quality Rules, Part 150-05-3 of this Title.

3. Method 1 GB Groundwater Objectives:

Groundwater which is classified as a GB area is presumed not suitable for use as a current or potential source of drinking water, and is subject to the GB Groundwater Objectives listed in Table 4, §1.9.3(F)(5) of this Part.

4. Table 3: GA Groundwater Objectives

GA Groundwater Objectives
Substance	GA Groundwater Objective (mg/l)
Volatile Organics
Benzene	0.005
Carbon tetrachloride	0.005
Chlorobenzene	0.1
1,2-Dibromo-3-chloropropane (DBCP)	0.0002
1,2-Dichloroethane	0.005
1,1-Dichloroethene	0.007
cis-1,2-Dichlorothene	0.07
trans-1,2-Dichloroethene	0.1
1,2-Dichloropropane	0.005
Ethylbenzene	0.7
Ethylene dibromide (EDB)	0.00005
Methyl tertiary-butyl ether (MTBE)	0.04
Methylene chloride	0.005
Styrene	0.1
Tetrachloroethene	0.005
Toluene	1
1,1,1-Trichloroethane	0.2
1,1,2-Trichloroethane	0.005
Trichloroethene (TCE)	0.005
Trihalomethanes (Total)	0.08
Vinyl chloride	0.002
Xylenes (Total)	10
Semivolatiles
Benzo(a)pyrene	0.0002
o-Dichlorobenzene	0.6
m-Dichlorobenzene	0.6
p-Dichlorobenzene	0.075
Diethylhexyl phthalate	0.006
Hexachlorobenzene	0.001
Naphthalene	0.10
Pentachlorophenol	0.001
1,2,4-Trichlorobenzene	0.07
Pesticides/PCBs
Chlordane	0.002
Polychlorinated biphenyls (PCBs)	0.0005
Inorganics
Antimony	0.006
Arsenic	0.01
Barium	2
Beryllium	0.004
Cadmium	0.005
Chromium (Total)	0.1
Cyanide	0.2
Lead	0.015
Mercury	0.002
Nickel	0.1
Selenium	0.05
Thallium	0.002

5. Table 4: GB Groundwater Objectives

GB Groundwater Objectives
Substance	GB Groundwater Objective (mg/l)
Benzene	0.14
Carbon Tetrachloride	0.07
Chlorobenzene	3.2
1,2-Dibromo-3-chloropropane (DBCP)	0.002
1,2-Dichloroethane	0.11
1,1-Dichloroethene	0.007
cis-1,2-Dichloroethene	2.4
trans-1,2-Dichloroethene	2.8
1,2-Dichloropropane	3.0
Ethylbenzene	1.6
Styrene	2.2
Methyl Tertiary-Butyl Ether (MTBE)	5.0
Tetrachloroethene	0.15
Toluene	1.7
1,1,1-Trichloroethane	3.1
Trichloroethene	0.54
Vinyl Chloride	0.002

G. Method 2 GB Groundwater Objectives:

1. Method 2 allows for the consideration of limited site-specific information to modify Method 1 GB Groundwater Objectives or to calculate GB Groundwater Objectives for Hazardous Substances in groundwater not listed in Table 4, §1.9.3(F)(5) of this Part, but which have the potential to volatilize. For the purposes of these regulations, a Method 2 GB Groundwater Objective shall refer to any groundwater objective which has addressed site-specific conditions pursuant to this rule and in accordance with the appropriate information presented in § 1.19 of this Part. The Department reserves the right to require the development of Method 2 GB Groundwater Objectives based on complicated conditions at the Contaminated-Site such as potential adverse impacts to adjacent surface water bodies, potential adverse impacts to surrounding GA/GAA areas or other potential impacts to human health and/or the environment.

2. Method 2 GB Groundwater Objectives may be developed for Hazardous Substances which do not have promulgated Method 1 GB Groundwater Objectives listed in Table 4, §1.9.3(F)(5) of this Part, or when conditions at the Contaminated-Site deviate significantly from the conservative assumptions used to calculate the Method 1 GB Groundwater Objectives as discussed in § 1.19 of this Part, provided that the resulting Method 2 GB Groundwater Objective is based on detailed site-specific information.

3. Method 2 GB Groundwater Objectives shall be consistent with §§1.9.1 and 1.9.3(D) of this Part and shall meet all of the following conditions in §§1.9.3(G)(3)(a) through (d) of this Part listed below.

a. The Method 2 GB Groundwater Objective shall be based, at a minimum, on the following:

(1) A scientifically acceptable volatilization model such as that described in § 1.19 of this Part; or

(2) Transport and fate modeling that incorporates site-specific information on the Hazardous Substances, hydrogeological conditions at the Contaminated-Site, current and reasonably foreseeable building conditions, and which demonstrates that contamination will not infiltrate to indoor air and result in significant risk of harm to human health or the environment; and/or

(3) Soil gas characterization data, indoor air characterization data, and data resulting from field investigation activities conducted at and proximate to the Contaminated-Site;

b. The Method 2 GB Groundwater Objectives shall not result in indoor or ambient air concentrations which pose a significant risk of harm to human health or the environment;

c. If the development of a Method 2 GB Groundwater Objective results in a concentration of a Hazardous Substance which exceeds any Upper Concentration Limit as described in §1.9.7 of this Part, then the Department reserves the right to require that the modification be adjusted downward to a concentration which prevents the exceedance; and d. Method 2 GB Groundwater Objectives shall be scientifically justified and sufficiently documented to demonstrate that the developed objectives are protective against migration of Hazardous Substances into indoor air or any other site-specific considerations. At a minimum, Method 2 GB Groundwater Objective development shall be documented with sufficient information to allow the Director to evaluate the following:

(1) The appropriateness and validity of any chemical-specific and/or site-specific input parameters used;

(2) Whether the calculations, modeling or sampling were correctly performed;

(3) The potential for groundwater at the Contaminated-Site to pose significant risk to human health and the environment after the proposed Method 2 GB Groundwater Objectives are applied to the Contaminated-Site as part of a Remedial Action; and

(4) Background levels for the applicable Hazardous Substances, if determined.

1.9.4Method 3 Remedial Objectives:

A. Advanced approval of the Director shall be required prior to proposed use of Method 3 Remedial Objectives.

B. Advanced approval of all Owners shall be required prior to proposed use of Method 3 Remedial Objectives.

C. A $20,000 application fee shall be submitted to the Department at the time the Performing Party requests review and/or approval of a proposed risk assessment for Method 3 Remedial Objectives. The Director may also require a Performing Party to reimburse the Department for costs, and expenses incurred, including but not limited to contractor support services, as part of accepting proposals to utilize Method 3 Remedial Objectives at a Contaminated Site. Final approval shall be at the discretion of the Director.

D. Method 3 Remedial Objectives allow for a site-specific risk assessment to be conducted by the Performing Party on either a voluntary basis, or as required by the Director, subject to requirements of §1.9.1 of this Part, and to the extent appropriate to §§1.9.2(B) and 1.9.3(D) of this Part.

E. Site-specific human health risk assessments shall be conducted only after review and approval of a Human Health Risk Assessment Workplan, submitted in both hard copy and electronic format (as specified by the Department), by the Department. The methodology proposed in the Human Health Risk Assessment Workplan shall be consistent with scientifically acceptable risk assessment practices and the fundamentals of risk assessment under EPA's "Risk Assessment Guidance for Superfund," incorporated above at § 1.3(B) of this Part. The Human Health Risk Assessment Report, when completed according to the approved workplan, shall propose remedial objectives for all impacted environmental media, as appropriate.

F. In addition, in reviewing the site-specific Method 3 Remedial Objectives derived pursuant to this rule, the Director may evaluate the following factors:

1. The potential for any remaining Hazardous Substances to pose a significant threat to human health or the environment;

2. Correct application of the approved methodology;

3. The management of risk relative to any remaining contamination;

4. Background levels for the applicable Hazardous Substances; and

5. Circumstances related to the practicality of remediation.

G. Method 3 Remedial Objectives shall also be utilized to develop remedial objectives which are protective of Environmentally Sensitive Areas. To the extent that remedial objectives protective of Environmentally Sensitive Areas are required by the Director, the Performing Party shall develop such remedial objectives in accordance with §1.9.5 of this Part.

H. If any Method 3 Remedial Objective results in an exceedance of any Upper Concentration Limit as described in §1.9.7 of this Part, then the Department reserves the right to require that the Method 3 Remedial Objective be adjusted downward to a concentration which prevents the exceedance.

1.9.5Ecological Protection

A. Based on information provided in the Notification, Site Investigation or any other source, if a Release of Hazardous Materials has the potential to adversely impact an Environmentally Sensitive Area, then the Director may require the following, including but not limited to:

1. An Ecological Risk Assessment, conducted in accordance with EPA/630/R-92/001 "Framework for Ecological Risk Assessment," incorporated above at § 1.3(C) of this Part, or functional equivalent. The Ecological Risk Assessment shall be conducted only after Department review and approval of an Ecological Risk Assessment Workplan, submitted in both hard copy and electronic format (as specified by the Department); and

2. An Ecological Risk Assessment Report, submitted in both hard copy and electronic format (as specified by the Department), which proposes remedial objectives demonstrated to mitigate any risks to the impacted media identified in the Ecological Risk Assessment. Soil objectives which result from the Ecological Risk Assessment Report shall be considered Method 3 Soil Objectives.

1.9.6Background Concentrations for Soil:

A. Sampling of Hazardous Substances in background areas may be conducted to distinguish concentrations related to the Contaminated-Site from concentrations of Hazardous Substances not related to activities at the Contaminated-Site or to support the development of soil objectives under the provisions of §1.9.2 of this Part.

B. For purposes of defining background concentrations, samples shall be collected from areas that have the same characteristics as the soil at the Contaminated-Site, and meet the definition of background.

C. In order to evaluate or justify available data for the purposes of defining background concentrations, a Performing Party shall use a statistical method which is appropriate for the distribution of each Hazardous Substance and such method shall utilize a minimum of twenty (20) samples. If the distribution of the Hazardous Substance data is inappropriate for statistical methods based on a normal distribution, then the data may be transformed. If the distributions of individual Hazardous Substances differ, more than one statistical method may be required at a Contaminated-Site.

Based on the statistically significant number of samples previously evaluated by the Department and on file to make the background determination for arsenic across the state, the requirements of § 1.13 of this Part shall apply to evaluate arsenic in soil.

D. For purposes of estimating background concentrations, values below the method detection limit shall be assigned a value equal to one-half of the method detection limit. Measurements above the method detection limit, but below the practical quantitation limit shall be assigned a value equal to the method detection limit. The Department may approve the use of alternate statistical procedures for handling data below the method detection limit or practical quantitation limit.

1.9.7Upper Concentration Limits

A. Upper Concentration Limits in soil, sediments, and water are concentrations of Hazardous Substances, or petroleum which, if exceeded, may demarcate a transition between contaminated environmental media and waste in the environment. Upper Concentration Limits are not clean-up standards. Upper Concentration Limits may not be applicable to soil which has been immobilized as part of an approved remedial response action.

B. All remedial objectives shall address the following concentrations or conditions:

1. The presence of non-aqueous phase liquids (NAPL) in any environmental medium shall be considered a condition that exceeds Upper Concentration Limits;

2. The Upper Concentration Limit for TPH in soil is 30,000 ppm;

3. The Upper Concentration Limit for any Hazardous Substance in soil is 10,000 ppm; and

4. Table 5, §1.9.7(B)(5) of this Part lists the Upper Concentration Limits in GB groundwater that are protective against potential explosive conditions due to the volatilization of Hazardous Substances in groundwater to structures where human exposures cannot be reasonably expected to occur (§ 1.19 of this Part).

5. Table 5: Upper Concentration Limits for GB Groundwater

Upper Concentration Limits for GB Groundwater
Substance	GB Groundwater UCL (mg/l)
Benzene	18
Chlorobenzene	56
1,2-Dichloroethane	670
1,1-Dichloroethene	23
cis-1,2-Dichloroethene	69
trans-1,2-Dichloroethene	79
1,2-Dichloropropane	140
Ethylbenzene	16
Styrene	50
Toluene	21
1,1,1-Trichloroethane	68
Trichloroethene	87

1.9.8Points of Compliance:

A. Points of Compliance for Soils:

1. The points of compliance for soils are points where the soil objectives established under §§1.9.2 or 1.9.4 of this Part shall be attained. For soil objectives based on direct exposure to humans engaged in residential or industrial/commercial activities, the point of compliance shall be established in the soils throughout the Contaminated-Site, except as otherwise specified in §1.9.2(B)(1) of this Part (General Requirements for Direct Exposure Criteria). For soil objectives based on protection of GA/GAA or GB areas, the points of compliance shall be established throughout the Contaminated-Site in a manner consistent with §1.9.2(B) (2) of this Part (General Requirements for Leachability Criteria).

2. For a contiguous volume of contaminated soil which is determined to pose risks associated with direct exposure to humans engaged in residential and industrial/commercial activities, separate and distinct points of compliance may be proposed, provided that such points of compliance are consistent with §1.9.2(B)(1) of this Part (General Requirements for Direct Exposure Criteria) and are demonstrated to ensure protection of both residential and industrial/commercial activities. Such points of compliance are subject to the approval of the Director.

3. The Performing Party shall take affirmative steps to manage the Contaminated-Site such that the Contaminated-Site does not impact property which is not within the control of Performing Party, by ensuring that, at a minimum, the following requirements are met:

a. The concentration of any Hazardous Substance in soil does not exceed the Method 1 Residential Direct Exposure Criterion as described in §1.9.2 of this Part (Soil Objectives) and as specified in Table 1, §1.9.2(C)(2) of this Part at any point beyond the control of the Performing Party;

b. The Direct Exposure Criteria which is applied to the full areal extent which is under the control of the Performing Party does not present threats to human health and the environment at any point within that control pursuant to §§1.9.1, 1.9.2 or 1.9.4 of this Part (Remedial Objectives, Soil Objectives, and Method 3 Remedial Objectives) as appropriate; and c. The Performing Party shall provide formal written documentation to the Department demonstrating the Performing Party's control over the full areal extent of the Method 1 Residential Direct Exposure Criterion exceedance including, but not limited to the following, as appropriate:

(1) Documented acceptance of any residential direct exposure criterion developed pursuant to §1.9.4 of this Part (Method 3 Remedial Objectives) and all supporting documentation used in their derivation from all land Owners whose property is impacted by the Release; and

(2) An environmental land usage agreement entered into by all impacted land Owners pursuant to §1.9.9 of this Part (Institutional Controls), if the exposure assumptions made in the development of the Method 3 Remedial Objective are such that they need to be institutionally maintained in order to guarantee long-term protection of human health and the environment.

4. For a Contaminated-Site that is determined to actually or potentially impact GA/GAA and GB areas, separate and distinct points of compliance for soils may be proposed, provided that such points of compliance are consistent with §1.9.2(B)(2) of this Part (General Requirements for Leachability Criteria) and are demonstrated to ensure compliance with both GA and GB Groundwater Objectives.

5. Points of compliance for soils based on impacts to Environmentally Sensitive Areas shall be established throughout the Contaminated-Site or as determined in the ecological risk assessment performed in accordance with §1.9.5 of this Part (Ecological Protection).

B. Points of Compliance for Groundwater:

1. Points of Compliance with the GA Groundwater Objectives Any point where the groundwater quality is monitored or where groundwater is withdrawn for use, excepting points within a discharge zone or residual zone approved pursuant to the Department's Groundwater Quality Rules, Part 150-05-3 of this Title, may be used to determine compliance with the groundwater objectives for the area. Points of compliance with GA Groundwater Objectives may be on, or in close downgradient proximity to, the Contaminated-Site.

2. Points of Compliance with the GB Groundwater Objectives:

a. Points of compliance with GB Groundwater Objectives shall be established at locations which provide ample warning prior to groundwater flow into, under and around structures. Specifically:

(1) Points of compliance with the GB Groundwater Objectives shall be established along a line situated approximately thirty (30) feet (or any other appropriate and hydrologically defensible distance approved by the Director) laterally from any facility structure boundary, including, but not limited to utility conduits and structures such as sewer lines and pump houses;

(2) These points of compliance shall be situated along this line in a manner consistent with the groundwater flow direction;

(3) The spacing between points of compliance on the line will depend on site-specific information such as size of the structure, and shall be managed in such a way as to provide sufficient information regarding any potential impacts from contaminated groundwater volatilizing to indoor air;

(4) These points of compliance may be in addition to points of compliance designated for source control activities; and

(5) The Department reserves the right to require additional or separate points of compliance based on site-specific circumstances;

b. The Performing Party shall take affirmative steps to eliminate migration of any Hazardous Substance in groundwater to a GB area which is not under the control of the Performing Party, by ensuring that, at a minimum, the following requirements are met:

(1) The concentration of the Hazardous Substance in groundwater does not exceed the Method 1 GB Groundwater Objective as specified in Table 4, §1.9.3(F)(5) of this Part at any point beyond the control of the Performing Party; and

(2) The GB Groundwater Objective which is applied to the full areal extent which is under the control of the Performing Party does not present threats to human health and the environment at any point within that control pursuant to §§1.9.1, 1.9.3(D), 1.9.3(G) or 1.9.4 of this Part (Remedial Objectives, General Requirements for Groundwater Objectives, Method 2 GB Groundwater Objectives, Method 3 Remedial Objectives), as appropriate;

c. The Performing Party shall provide formal written documentation to the Department demonstrating the Performing Party's control over the full areal extent of the Method 1 GB Groundwater Objective exceedance including, but not limited to the following, as appropriate:

(1) Documented acceptance of the GB Groundwater Objectives and all supporting documentation used in their derivation from all land Owners whose property is impacted by the Release; and

(2) An environmental land usage agreement entered into by all impacted land Owners pursuant to §1.9.9 of this Part (Institutional Controls), if the exposure assumptions made in the development of the GB Groundwater Objectives are such that they need to be institutionally maintained in order to guarantee long-term protection of human health and the environment.

d. Points of compliance for groundwater based on impacts to Environmentally Sensitive Areas shall be established throughout the Contaminated-Site or as determined in the ecological risk assessment performed in accordance with §1.9.5 of this Part (Ecological Protection).

1.9.9Institutional Controls

A. Performing Parties shall institute environmental land usage restrictions for all properties subject to final decisions which result in levels of Hazardous Substances greater than those protective against direct exposure associated with residential land usage; or are subject to final decisions under a variance pursuant to §1.14.3 of this Part (Variances) relating to a remedial objective pursuant to these regulations; or are subject to any final decisions based solely or in part on the limitation of reasonably foreseeable exposures to Hazardous Substances in any media; or are subject to institutional controls required under §1.13.6 of this Part.

B. The Owner(s) of the Contaminated-Site shall document their concurrence with this restriction by recording an Environmental Land Usage Restriction, and filing it with the Department. The standard format for this agreement can be found on the Department's Office of Land Revitalization and Sustainable Materials Management Site Remediation web page at

http://www.dem.ri.gov/programs/wastemanagement/site-remediation/#process The executed Environmental Land Usage Restriction shall run with the land, as recorded on the title(s) to the property (or properties) on which the Contaminated-Site is situated, and shall be binding on all Owners, successors and/or assigns. This notice, and the associated restrictions and controls shall be subject to approval by the Director and shall include provisions to accomplish all of the following:

1. Prohibit activities on the Contaminated-Site that may interfere with a Remedial Action and its operation and maintenance, long-term monitoring or other measures necessary to assure the integrity of the Remedial Action;

2. Prohibit activities that may result in human exposure to levels of Hazardous Substances that exceed the concentrations that have been determined to be protective of human health, or that may result in a Release of Hazardous Materials which was contained as part of the remediation;

3. Require prior notice to the Department of the Owner's intent to convey any interest in the Contaminated-Site. A conveyance of title, an easement, or other interest in the property or portion of the property shall not be consummated by the Owner without complete and full disclosure of the plans and procedures, and adequate and complete provision for the continued operation of the remedy and the prevention of Releases and exposures as described in §1.9.9(B)(2) of this Part;

4. Grant to the Department and its designated representatives the right to enter the property at reasonable times for the purpose of monitoring compliance with the Remedial Action; and

5. Describe the restrictions placed on the property and/or the allowable uses of the property.

C. A copy of the final, recorded notice shall be submitted to the Department within fifteen (15) days of the date that it is entered into the Land Evidence Records.

1.9.10Compliance Sampling:

A. A Contaminated-Site is considered by the Director to be compliant with the Remediation Regulations when it is demonstrated that the appropriate remedial objectives have been met at all Source Areas within the Contaminated-Site. This rule specifies procedures for determining compliance with the appropriate soil objectives and groundwater objectives applied to the Contaminated-Site. Compliance procedures with all other remedial objectives shall be determined on a site-specific basis. § 1.13 of this Part specifies requirements specific to arsenic in soil.

1. Compliance with the Soil Objectives:

a. All Performing Parties have, unless otherwise specified by the Director, two (2) alternatives for determining compliance with soil objectives. These alternatives are:

(1) A Performing Party may propose in the Remedial Action Work Plan to verify compliance by taking not less than twenty samples for laboratory analysis. This shall be accomplished by a representative sampling program used to characterize the distribution and concentration of Hazardous Substances at the former Source Area. The analytical results of all samples taken using this approach, including any and all specific samples which may be specified and/or taken by the Department, shall be below the appropriate soil objective in order for the Source Area to be considered compliant with these Regulations; or

(2) A Performing Party may propose in the Remedial Action Work Plan to verify compliance by geometrically gridding the former Source Area and taking not less than twenty compliance samples for laboratory analysis at the intersecting points of the grid. If a Performing Party utilizes this criteria they may also propose a statistical analysis methodology for determining compliance. The Department reserves the right to take or require additional compliance samples as warranted, and the statistical evaluation shall account for all samples taken. The methodology shall meet the following criteria:

(AA) No single sample result exceeds the soil objective by a factor of five (5);

(BB) No more than 10% of the individual sample results exceed the soil objective; and

(CC) No single sample result exceeds any Upper Concentration Limit as defined by §1.9.7 of this Part.

(DD) No compliance sampling plan shall be accepted that includes sample results outside the former Source Area in the statistical evaluation of results.

2. Compliance with the Groundwater Objectives:

Compliance with the groundwater objectives shall be determined through laboratory analysis of representative samples used to characterize the distribution and concentration of Hazardous Substances migrating from the Contaminated-Site. The analytical results of all samples taken using this approach shall be below the appropriate groundwater objective in order for the Contaminated-Site to be considered compliant with these Regulations.

1.9.11Remedial Objective Approvals

A. All remedial objectives shall be approved by the Department at one of two points in the site management process. These are:

1. §1.8.4 of this Part; or

2. §1.10.2 of this Part (Remedial Objectives).

250 R.I. Code R. 250-RICR-140-30-1.9

Amended effective 4/22/2020