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).

DTSCLarge 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 TWWDetermine whether the wood to be removed during projects is treated wood. See guidance
HandlingFollow overall recommendations. See guidance
StorageGenerators 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
LabelingAll TWW generated, accumulated, stored or transported by generators within California must be clearly marked and visible for inspection. See guidance for sample label.
TransportGenerators must follow specific requirements for consolidating TWW volumes and provide information that must accompany any shipments for disposal. See guidance
NotificationsGenerators 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
RecordkeepingGenerators 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
ReuseTreated wood removed from its current use can only be reused under specific conditions. See guidance
Disposal sitesTWW must be disposed only at authorized disposal sites. Find disposal site