Department of Toxic Substances Control Department of Toxic Substances Control

Regulatory Assistance for Due Diligence


Before you purchase property, and in order to make an informed decision about purchasing the land you need to conduct “all appropriate inquiries“ also known as “due diligence” to investigate and identify any potential environmental concerns which you would become liable for once you are the property owner.  Some concerns include past uses, which left the land “contaminated” with hazardous waste and contamination at nearby properties. 


All Appropriate Inquires Final Rule
This US EPA document explains the standards established for conducting All Appropriate Inquiries (AAI)

All Appropriate Inquiries Training
The Powerpoint presentation includes: background information on the AAI rule, AAI phase I ESA requirements and practices, key AAI activities and examples.

Initial Statement of Reasons - Phase I Environmental Site Assessment (Schools)
This document explains the rulemaking that affects California Code of Regulations, title 22, division 4.5, chapter 51.5 with the inclusion of sections 69100- 69107.

Initial Statement of Reasons - Amendment to Phase I Environmental Site Assessments (Proposed New and Expanding School Sites)
The document covers proposed rulemaking that would amend text pertaining to Phase I and Phase I Addendum processes.


Tiered Permitting Phase I Environmental Assessment Checklist (Instructions)
The checklist provides detailed instructions for completing and submitting the checklist.

Tiered Permitting Phase I Environmental Assessment Checklist (DTSC 1151)
Checklist only, no instructions.

Due Diligence for School Sites

DTSC's School Property Evaluation and Cleanup Division is responsible for assessing, investigating and cleaning-up proposed school sites.  The Division ensures that selected properties are free of contamination or, if the properties were previously contaminated, that they have been cleaned-up to a level that protects the students and staff who will occupy the new school.  All proposed school sites that will receive State funding for acquisition or construction are required to go through a rigorous environmental review and cleanup process under DTSC's oversight. See DTSC Schools Schools page for more information.

How do I determine if a property has been contaminated with methamphetamine

Chapter 6.9.1 Methamphetamine contaminated Property Cleanup Act of 2005

Gives the regulatory and legal specifications and requirements pertaining to meth contaminated properties

California Code of Regulations, Title 22, Chapter 14, Article 8 – Financial Requirements

Gives the regulatory financial requirements which would pertain to meth contaminated property

American Society for Testing and Materials (ASTM)   

Guidelines and standards relating to transactions of commercial real estate for performing a Phase 1, Phase 2 Environmental Assessment developed by ASTM.

Methamphetamine Contaminated Property Cleanup Act of 2005 – AB 1078/SB 536/AB 2587
This document outlines requirements for cleaning up meth contaminated property.  Contains links to other resources.