Approved sampling and analysis procedures

When investigating and cleaning up a contaminated site under the Model Toxics Control Act (MTCA) Cleanup Regulations, all sampling and analysis must be done using an Ecology-approved method, at an Ecology accredited lab. If we have not approved any applicable method, you can use a standard method or procedure such as those specified by ASTM International.

Sampling and analysis includes:

  • sample collection
  • handling
  • preservation
  • transportation
  • holding time
  • preparation
  • laboratory analysis
  • method detection limits
  • practical quantitation limits
  • quality assurance
  • quality control
  • data reporting
  • other technical requirements and specifications

Ecology-approved methods

We have approved the sampling and analytical methods referenced in the following sources for use under the MTCA Cleanup Regulations.

Approved sources and methods

Common approved methods

This table includes some commonly used analytical methods for specific hazardous substances and matrices from the sources above. It also has some additional analytical methods we’ve approved. This table does not include our approved analytical methods for sediment and aquatic tissue, which are in the Sediment Cleanup User's Manual (SCUM).

The methods are identified by the hazardous substance (or class of substances) and by the environmental matrix where the substance is sampled: drinking water, aqueous media (e.g., groundwater), solids (e.g., soil), and air.

Analyte Method Drinking water Aqueous Solids Air
Alkalinity SM 2320   yes    
Anions EPA 300.1 yes yes    
Anions EPA 9056A   yes yes  
Anions SM 4110 yes yes    
Arsenic EPA 16321   yes    
Asbestos EPA 600/R-93/116     yes  
Conductivity SM 2510   yes    
Cyanide SM 4500-CN   yes    
Cyanide EPA 9012B     yes  
Dioxins/Furans EPA 1613   yes yes  
Dioxins/Furans EPA 8290   yes yes  
Dissolved Oxygen SM 4500-O   yes    
Dissolved Oxygen Hach 10360   yes    
Grain Size Distribution ASTM D422     yes  
Grain Size Distribution ASTM D6913     yes  
Grain Size Distribution ASTM D7928     yes  
Grain Size Distribution PSEP 1986     yes  
Hexavalent Chromium EPA 7196A   yes    
Hexavalent Chromium SM 3500-Cr   yes    
Iron SM 3500-Fe 2   yes    
Leachate EPA 1311   yes yes  
Leachate EPA 1312   yes yes  
Mercury EPA 7470A   yes    
Mercury EPA 7471B     yes  
Mercury EPA 1630 3   yes    
Mercury EPA 1631E   yes    
Metals EPA 6010D 4   yes yes  
Metals EPA 6020B   yes yes  
Metals EPA 200.8 yes yes    
Metals EPA 1640   yes    
Organotins KRONE89     yes  
ORP SM 2580 yes yes    
PCBs EPA 1668C   yes yes  
PCBs EPA 680   yes    
PCBs EPA 8082A   yes yes  
Pesticides EPA 8081B   yes yes  
Pesticides EPA 680   yes    
Pesticides EPA 608.3   yes    
Petroleum NWTPH-HCID 5   yes yes  
Petroleum NWTPH-Gx   yes yes  
Petroleum NWTPH-Dx   yes yes  
Petroleum NWTPH-VPH   yes yes  
Petroleum NWTPH-EPH   yes yes  
Petroleum WSC-CAM-IX       yes
PFAS EPA 1633   yes yes  
PFAS EPA 8327   yes    
PFAS EPA 533 yes      
PFAS EPA 537.1 yes      
pH SM 4500-H+   yes    
pH EPA 9045D     yes  
Phenols EPA 8041A   yes yes  
Solids SM 2540 yes yes    
Sulfide EPA 9030B   yes yes  
Sulfide EPA 9034     yes  
SVOCs (incl. PAHs) EPA 8270E-SIM 6   yes yes  
TOC/DOC EPA 9060A   yes yes  
TOC/DOC SM 5310   yes    
Turbidity SM 2130   yes    
VOCs EPA 8021B   yes yes  
VOCs EPA 8260D 7   yes yes yes
VOCs EPA TO-15A       yes
VOCs EPA TO-17       yes

Table footnotes

  1. This method measures arsenic species: total inorganic arsenic (As), arsenite (As3+), arsenate (As5+), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA).
  2. This method can quantitate total iron as well as ferrous (Fe2+) and ferric (Fe3+) iron.
  3. Use this method for methyl mercury analysis.
  4. This method should not be used for mercury analysis.
  5. Qualitative/semi-quantitative method to identify presence and type of hydrocarbons; for quantitative results, use other NWTPH methods.
  6. Lower reporting limits are achieved using selected ion monitoring (SIM) and even lower levels can be achieved using isotope dilution (e.g. for very low-level 1,4-dioxane analysis); this method is used for carcinogenic PAHs (benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, chrysene, dibenz[a,h]anthracene, and indeno[1,2,3-cd]pyrene).
  7. Not recommended for 1,4-dioxane (use EPA 8270E-SIM instead).

Changes to the approved methods

We will update the list of approved methods as needed. When we add or remove a method from this list, we will announce it in the Contaminated Site Register. Anyone may propose another method for Ecology review and approval.

Which Ecology-approved methods should I use at my site?

The sampling and analytical methods you use must be appropriate for the contaminated site, the media being analyzed, the hazardous substances being analyzed for, and the anticipated use of the data. Under certain circumstances we may require modifying a method or using more than one method.

Petroleum releases have specific minimum testing requirements, found in Table 830-1 in WAC 173-340-900.

Always use an Ecology-accredited laboratory

All environmental data submitted to Ecology must be generated by an Ecology-accredited laboratory, unless otherwise approved by Ecology.

Make certain that the laboratory is accredited for the specific analytical method and environmental matrix you need. A laboratory might be accredited for only certain methods or matrices (such as for solid and chemical materials, but not specifically for aqueous or air). Note some methods accredited for solid and chemical materials cover some aqueous or air samples. Check our Lab Search database to find which labs are accredited for a specific analytical method and environmental matrix or to list the specific analytical methods for any accredited lab.