Sampling Requirements & Action Levels
Spill Investigation Program
Clean-up confirmation sampling is an essential part of any remediation. Laboratory sample
results are required to be submitted to the NDDEQ as proof of successful remediation.
Laboratory and Sampling Requirements
The laboratory used must have an active North Dakota Environmental Laboratory Certification
Program (NDELCP) certification. Reach out to the laboratory to confirm certification status
and for additional information regarding sample collection and transportation requirements.
For excavated sites, confirmation samples should be taken at a rate of one (1) sample per
100 square feet of the base of the excavation and each excavation sidewall. Sample frequency
requirements for very large spills or other remediation methods are determined by the scope
of the project but should be sufficient to fully characterize the site.
The confirmation sample analyses are dependent on the material spilled. Below are some
common spilled materials and the analyses that will be required. Analyses for materials not
listed will be determined on a case-by-case basis dependent on the material spilled.
The full technical requirements are in the
Guidelines for the Assessment and Remediation of Oilfield Releases, Section 10
.
Analytical Requirements by Material and Media
Crude Oil, Emulsion, or Saltwater — Spills into Water
| Constituent |
Analytical Method |
| Chloride | EPA Method 300.0 |
| % Sodium | Calculated |
| Sulfate | EPA Method 300.0 |
| Alkalinity | Standard Method 2320B |
| TDS | Calculated or Gravimetric |
| Benzene | EPA Method 524.4 |
| Toluene | EPA Method 524.4 |
| Ethylbenzene | EPA Method 524.4 |
| Xylenes | EPA Method 524.4 |
| Ammonium | EPA Method 350.1 |
| Bromide | EPA Method 300.0 |
| pH | Field Measured |
| Total Petroleum Hydrocarbons (TPH) | Any EPA approved method |
Crude Oil, Emulsion, or Saltwater — Spills into Soil
The NDDEQ will allow any soil analytical method, provided the method detection limit is of sufficient sensitivity to adequately characterize any impacts and verify remediation. Required constituents:
- Chloride
- SAR
- Sulfate
- EC
- Bromide
- % Sodium
- pH
- Total Petroleum Hydrocarbons (TPH)
Benzene, Toluene, Ethylbenzene, and Xylene analyses may be required depending on the size and location of the spill.
Gasoline, Diesel, or Liquefied Natural Gases — Spills into Water
| Constituent |
Analytical Method |
| Benzene | EPA Method 524.4 |
| Toluene | EPA Method 524.4 |
| Ethylbenzene | EPA Method 524.4 |
| Xylenes | EPA Method 524.4 |
| Total Petroleum Hydrocarbons (TPH) | Any EPA approved method |
Diesel, Gasoline, or Liquefied Natural Gases — Spills into Soil
The NDDEQ will allow any soil analytical method, provided the method detection limit is of sufficient sensitivity to adequately characterize any impacts and verify remediation. Required constituents:
- Benzene
- Toluene
- Ethylbenzene
- Xylenes
- Total Petroleum Hydrocarbons (TPH)
Common Remediation Action Levels
Common remediation action levels can be found below. This is not a comprehensive list,
and action levels for other materials are based on the
NDDEQ Water Quality Standards
.
In water:
| Constituent |
Action Level |
| Chloride | 250 mg/L |
| Total Petroleum Hydrocarbons | 0.5 mg/L |
| Benzene | 0.058 mg/L |
| Toluene | 0.520 mg/L |
| Ethylbenzene | 0.130 mg/L |
| Xylenes | 10 mg/L |
In soil:
| Constituent |
Action Level |
| Chloride | 250 ppm |
| Total Petroleum Hydrocarbons (TPH) | 100 ppm |
