Proposed Waiver of WDRs for Reuse of Inert Waste Containing Metals

1. Proposed Waiver of WDRs for Reuse of Inert WasteContaining Metals

2. Waiver re Reuse of Inert Waste Members of the Technical Working Group: Dan Johnson, John Anderson and Dave Barker � RWQCB George McCandless � DEH Steve Beck � Ninyo & Moore Linda Beresford � Opper & Varco LLP Julie Marshall � Rincon Environmental Gary McCue � TRC Tom Mills � Leighton Consulting Tom Mulder � TN & Associates Doug Roff � Earth Tech Nathan Starr � Amec Earth & Environmental

3. Waiver re Reuse of Inert Waste Purpose: To provide a framework for the reuse of excess soils following a site investigation or remediation for identified Chemicals of Concern (�COCs�). Waiver provides a two-tiered approach Tier I: allows for unrestricted reuse of soil Tier II: allows for restricted reuse of soil COCs covered by the Waiver are those listed in Table 1

4. Waiver re Reuse of Inert Waste Step One: Investigate the Site for suspected COCs If investigation data meets the criteria set forth in Tier I or Tier II, soil can be reused in accordance with those standards If investigation for suspected COCs shows that some soil has been impacted by a release, then the soil should be segregated into 2 categories Step Two: Soil impacted by the release should be handled pursuant to regulatory standards Step Three: Remaining soil that meets either Tier I or Tier II criteria can be reused in accordance with the waiver standards

5. Waiver re Reuse of Inert Waste Candidate soil for reuse under the Waiver shall be sampled and tested for the identified COCs to determine if the soil meets the waiver criteria Sample protocol: Volume of Soil Number of samples required 0 to 500 cubic yards 4 samples/ 100 cu yds � 12 samples min >500 to 5,000 cu yds 1 addtl sample per addtl 500 cu yds >5,000 cubic yards 1 addtl sample per addtl 1,000 cu yds Volumes greater than 10,000 cubic yards may rely on fewer samples than 1 per 1,000 cubic yards, if characterization complies with SW846 methods for waste characterization and statistical analyses

6. Waiver re Reuse of Inert Waste Samples shall be analyzed by an SW846 method using the reporting limits set forth in Attachment 1 From these data, the 80% upper confidence level shall be determined Additional requirements re sample statistics (re normal vs. non-normal distribution) discussed in the waiver

7. Waiver re Reuse of Inert Waste So � what is the Tier I level allowing for unrestricted reuse? For Lead: 15 mg/kg How do we determine this? The Designated Level Methodology

8. Waiver re Reuse of Inert Waste Designated Level Methodology � cleanup level determination expressed as mass of contaminant divided by mass of dry soil (mg/kg) Developed by Central Valley RWQCB Water Quality Goal x Environmental Attenuation Factor x Leachability Factor Supporting documents recommend 100 as an appropriate �generic� Environmental Attenuation Factor Appropriate groundwater Dilution Attenuation Factor: 90th percentile DAF value is 100 or higher for a waste area of 1 acre or less; for waste areas of 10 acres and greater, the 90th percentile DAF is 10 or less

9. Waiver re Reuse of Inert Waste DLM for Lead for Tier I: Water Quality Goal: .015 mg/L Environmental Attenuation Factor: 10 Leachability Factor: 100 Total Designated Level: 15 ug/L x 10 x 100 = 15 mg/kg Same formula was used as guideline for other contaminants in COC Table

10. Waiver re Reuse of Inert Waste Soluble Designated Level - Tier II Water Quality Goal x Environmental Attenuation Factor For Lead: 15 ug/L x 10 = 150 ug/L (To be determined by SPLP testing or Column Testing)

11. Waiver re Reuse of Inert Waste Tier I Level Conditions: Soil with an 80% UCL of 15 mg/kg or less of total lead is suitable for export and unrestricted reuse Value is consistent with studies of background levels and was below known human health and ecological risks values For other COCs, the Tier I Levels are set as the lowest value among the Total Designated Level and applicable human health and ecological risk-based screening values For metals that naturally occur at concentrations greater than the TDL or applicable risk-based screening values, the Tier I Level is set as the high estimate of the naturally occurring background concentration (Review Table/Review Testing Limits)

12. Waiver re Reuse of Inert Waste Tier II Criteria: Soil with an 80% UCL between 15 and 150 mg/kg total lead and an 80% UCL of 150 ug/L or less of soluble lead (from SPLP or column testing as described in Attachment 2 to waiver) is suitable for export and restricted reuse Review Table Column Testing

13. Waiver re Reuse of Inert Waste Tier II Reuse Restrictions - receiving site must meeting the following conditions: Site shall not be located in an area dependent on groundwater for the sole source of drinking water Inert waste shall be placed at least five feet above the highest anticipated level of ground water The soil separating the inert waste from groundwater shall have a significant clay content (greater than 5% clay-sized material) or an in-situ permeability of less than 10-5 cm/sec Inert waste shall be placed at least 100 feet from the nearest surface water Inert waste shall be protected against 100-yr peak stream flows Inert waste shall be covered by engineered materials or not less than 2 feet of noncontaminated clean fill with permeability of no more than 10-5 cm/sec

14. Waiver re Reuse of Inert Waste Soils with multiple COCs must also be evaluated for cumulative risks with respect to each COC Step 1: Identify the COC under evaluation Step 2: Record the Total Designated Level for each COC Step 3: Calculate the cumulative hazard ratio by taking the calculated 80% UCL and divide that number by the respective TDL for each COC and add them together

15. Waiver re Reuse of Inert Waste Total Hazard Ratio = concx +concy + concz TDLx TDLy TDLz A total hazard ratio of one or less is acceptable for reuse under this Waiver A total hazard ratio greater than 1 suggests that further evaluation is necessary and the soil is not eligible for reuse under this Waiver Carcinogens and noncarcinogens should be summed separately; each must sum to 1 or less.

16. Waiver re Reuse of Inert Waste Other Waiver Requirements: Waiver Certification and Supporting Information must be submitted to RWQCB Certification must be signed by representative of export site and a Professional Engineer or Geologist Certification states that the signatories have examined and are familiar with the information submitted and that the information is true, accurate and complete

17. Waiver re Reuse of Inert Waste The report shall contain the following information: General export site condition Summary of analytical data for the COC and the export soil, including minimum, maximum and 80% UCL with a map showing sample locations Temporary Inert waste pile information Storm water/erosion control BMPs for the export site

18. Waiver re Reuse of Inert Waste Tier II Report information shall also include: General export and receiving site conditions Total and soluble concentrations for the COCs for exported soil The disposition of the inert waste (i.e., location to groundwater, type of cover, etc.) Maintenance activities at the receiving site Property owner acknowledgement re receipt of the inert waste

19. Waiver re Reuse of Inert Waste The proposed waiver also includes a waiver of WDRs for discharges of inert wastes to temporary waste piles Identical to protocol included in other waivers adopted by the RWQCB Included here because unclear if a general waiver re temporary waste piles was going to be adopted

20. Waiver re Reuse of Inert Waste Copies of proposed waiver and technical paper supporting the waiver are posted on the Opper & Varco LLP website: www.envirolawyer.com at Resources/State Resources RWQCB held CEQA scoping meeting on April 5. Technical document with analysis of all waivers to be released for comment in June/July 2007 RWQCB staff is currently evaluating this waiver and may still request some changes � hope to finalize this waiver by mid-May Goal is to submit all proposed waivers and general WDRs for readoption to the RWQCB in September