Generators
Guidance for companies with large volumes of TWW
Companies that are either generating or handling large volumes of TWW have mandated responsibilities in not only properly disposing, but in recordkeeping and reporting to the California Department of Toxic Substances Control (DTSC).
Large generators, those handling more than 10,000 lbs. of TWW in a calendar year, must review requirements for storage, labeling, transportation, notifications and recordkeeping. Go to the specific topic under the TWW Basics section for detailed guidance.
| Identifying TWW | Determine whether the wood to be removed during projects is treated wood. See guidance |
| Handling | Follow overall recommendations. See guidance |
| Storage | Generators must follow specific requirements in storing TWW to prevent unauthorized access and minimize run-off. These include blocking and tarping, containerizing, storage buildings, containment pads and other methods. TWW may not be accumulated for more than one year from the date of generation. See guidance |
| Labeling | All TWW generated, accumulated, stored or transported by generators within California must be clearly marked and visible for inspection. See guidance for sample label. |
| Transport | Generators must follow specific requirements for consolidating TWW volumes and provide information that must accompany any shipments for disposal. See guidance |
| Notifications | Generators handling more than 10,000 lbs. of TWW in a calendar year must register and notify the state. Generators must apply for a state identification number and complete a DTSC notification form within 30 days of exceeding the 10,000 lbs. threshold. See guidance |
| Recordkeeping | Generators are required to keep records of TWW disposal, which may take the form of a log, invoice, manifest, bill of lading, shipping document, or receipt from an approved TWW facility. Such records must be maintained for a minimum of three years. See guidance |
| Reuse | Treated wood removed from its current use can only be reused under specific conditions. See guidance |
| Disposal sites | TWW must be disposed only at authorized disposal sites. Find disposal site |
Guidance – Generators
Click image above to download guidance publication for TWW Generators.
Guidance – Large Generators
Click image above to download guidance publication for TWW Large Generators.