1. 2016 Solid Waste Program Groundwater Initiatives A Summary Review Virginia DEQ October 2015

2. Groundwater Initiatives Under drains: adding consistency and clarity to the permitting, monitoring, and reporting process. Groundwater User Survey: updating information regarding on site as well as adjacent property groundwater use to make better risk management decisions in Corrective Action. Alternate Remedy Use in GW CA: understanding when the status quo is no longer appropriate.

3. Monitoring of Under drain (and related) Collection Systems at Solid Waste Landfills

4. Defining The Issue Some LF Permits contain requirements to sample liquid discharges from: 1.Under drains, 2.Gradient control (i.e., dewatering) systems, 3.A witness zone, 4.Piped stream, or 5.Seep/spring-box collection systems. But ……

5. Current Status Statewide, there is little consistency in: 1.the Permit Modules in which these requirements are defined, 2.sampling parameters required in the Permit, 3.How the results are reported, or 4.the benchmarks the sample results are compared against to identify a problem. We need to strive for consistency across the Commonwealth on how these features are treated in Permits.

6. Why Do We Care About These Systems? LF liners and leachate collection systems are designed ‘not to leak’ or cause discharge to groundwater or state waters (unless that discharge is covered by a VPDES Permit). Sampling of the water collected below the LF footprint (regardless of how it is collected) serves as a ‘performance’ tool to assess the adequacy of the liner/leachate system design and operation. not The goal is … not … to assess groundwater impact below the waste footprint (because that groundwater is exempt from monitoring under 40 CFR 258 and the VSWMR).

7. How to Permit and Assess Performance of these Systems? Requirements should be in the Permit (Part A/Part B/Pre-existing), but not in GW Modules (X and XI) because regulated groundwater is not being sampled, nor are monitoring wells involved in the sampling). Permits need to contain the appropriate ‘standards’ the analytical results must be compared to. Sampling for the Table 3.1 column A and/or B groundwater constituent list appears to be ‘more than is needed’, … you are just looking for signs of leachate.

8. Goal #1 Module XXI Remove all references for under drains and related systems sampling and analysis actions from Module X and XI (as well as the associated groundwater monitoring plan [GMP]). Place these requirements in: Module I Module I (for old format permits) Module III, IV, or V Module III, IV, or V (for streamlined Permits) Within a stand alone Under drain system monitoring plan [UDMP]

9. Goal #2 not Sampling list for CDD/IND/CCR LFs should not include VOCs … only common leachate indicator parameters such as Chloride, Alkalinity, TSS, TKN, BOD, COD, Boron (CCR-LFs). Sampling for specific metals keyed to the waste mass content could be added on a site specific basis. Sanitary LF Sanitary LF list would include Table 3.1 column A VOCs. Indicator parameters listed to the left could be added to if needed. Sampling for the common LF metals should be avoided in an effort to reduce the need for verification sampling or Alternate Source Demonstration submittals.

10. Goal #3 surface water In the case of surface water collected in piped streams, the end of pipe results should be compared to upstream (pre- inlet) sampling results obtained the same day. DEQ recommends that the facility have the means to also accurately measure in-flow volume and outfall volume in the case of piped streams since there should not be any extra contribution of liquids entering the pipe system beneath the waste mass.

11. Goal #3 cautionary note VOC, by definition are volatile. Sampling for VOC at the open air end of pipe may lead to collection of false-negative data at sanitary LFs. If possible, the collected water should be sampled internally if the system design permits … not at the end of pipe. Those Sanitary LF sites that lack internal sampling options should consider using a sampling list of the non-volatile indicator parameters.

12. Goal #4 Permits will specify the frequency of sampling and the sampling list. Sampling results shall be submitted to DEQ to the attention of your solid waste inspector..., once a year. DEQ has developed a fill in the blank type Submission Instruction (SI) for use in result submittals so that everyone is submitting information in a consistent manner/format. If the sampling results from an event suggest a non-performance issue with the liner/leachate collection system, the owner/operator shall notify DEQ within the defined timeframe in the Permit, and...

13. Goal #5 Take actions to ensure that leachate impaired Under drain system water is not being allowed to discharge from the end-of-pipe unless the discharge is governed by an appropriate VPDES permit or the discharge is captured and re-routed to a leachate collection system. Coordination with DEQ Water may be required in cases such as these and/or consultation with your RO solid waste permit writer if site modifications are needed. These modifications must be completed as soon as possible.

14. As A Result of the New Path These non-groundwater related requirements will now be in a consistent place in solid waste Permits going forward. They will appear in an Under drain monitoring plan (UDMP) not a groundwater monitoring plan (GMP). All sites with similar system designs will have consistent benchmarks to compare their sampling data to. All sites will have a sampling list that is appropriate for determining non- performance issues with their liner/leachate collection systems. These new sampling lists will likely offer cost reduction compared to existing sampling requirements. The sampling results will be submitted in a consistent format.

15. Forthcoming Tools Under drain Submission Instructions (i.e., how the sampling results will be submitted to DEQ). Boiler plate Under drain permit module language (e.g., language that will be common to nearly all affected Permits). A general Power Point training presentation, similar to this one to be posted on the DEQ website with more information on the background to this issue and how to modify your existing Permit.

16. Under drain Questions/Concerns

17. GW User Survey – Who’s Using What and Where?

18. Issue LFs that have exceeded GPS have known impacts to the local aquifer. To ensure accurate risk management decision making – DEQ needs to know if and how groundwater is being used onsite as well as on any of the adjoining properties. Aquifer usage onsite or on adjacent properties can affect groundwater flow rates and directions beyond that which would be assumed by looking at monitoring wells. This information may affect remedy selection/performance.

19. Data Gathering LFs that have exceeded GPS (approx. 100 sites) were sent a short survey to fill out regarding potable and non-potable groundwater use onsite and on adjacent properties. The survey is to be completed by the owner/operator or their environmental consultant prior to the end of the year, based on the most recently available data. Results will be reviewed by the Regional Office. If questions remain, or there is a concern regarding any current corrective action remedy applied on site, follow-up site visits/investigations may be required.

20. User Survey Questions/Concerns

21. GW CA – Use of Alternate Measures under 9 VAC 20-81-260

22. Remedy Choices in Solid Waste (85% of sites) -> Monitored Natural Attenuation (MNA) as stand- alone or combined with an area specific, additional remedy. (15%) -> Groundwater interception/extraction (w/out treatment), Groundwater pump and treat (w/VPDES), Insitu/Enhanced Bioremediation, or stand alone Presumptive Remedy. *MNA often chosen under the assumption “it’s cheaper to go that route”. This may not be true long term.

23. Remedy Success Affected By - Composition of the waste mass (pre-1980, ok to contain bulk liquid hazardous waste in solid waste landfills). Complexity Complexity of the aquifer (Coastal Plain sandbox (pretty simple) vs. Valley & Ridge karst (worst case scenario)). Depth Depth to GW (shallow GW = more remedial options may work) Rate Rate of GW flow (faster the flow = more likely plume is also longer, thus more area to be treated). Direction Direction of GW flow (if offsite, remedy choice will need to be more aggressive). Proximity Proximity to surface water (cross media transfer of CoC’s).

24. Have Any Sites Finished CA? Observations from Virginia: About a half dozen SWLFs have completed GW CA. All had relatively small-sized GW plumes to begin with. Plumes were confined within the permitted facility boundaries. Plumes did not discharge to surface water. Typically there were three or less VOC CoC’s involved. Levels exceeding GPS were not that significant at the start of CA. *These factors make it relatively ‘easy’ to achieve the VSWMR GW CA requirements within a 10-yr timeframe using MNA or another more aggressive approach.

25. What’s Happening at Sites in CA? Observations from Virginia: About a dozen SWLFs have shown “worsening” GW conditions since beginning GW CA. Most had incompletely defined the extent of their plume(s) vertically or horizontally in the NES phase, or Had underestimated GW flow rate significantly, thus underestimating the length of the GW plume. Several have had plume expansion off site. Several have had additional GPS exceeding CoC’s pop up since initial GW CA was undertaken. *Incomplete site characterization at the front end will catch up to you later.

26. What About Stalled Sites? Observations from Virginia: The vast majority of MNA sites show little, to marginal, improvement in GW since beginning GW CA. Plume(s) display ‘stable’ behavior (i.e., not expanding or contracting). If plumes continue discharge to surface water, most exceeding CoC’s do not, or have not, exceeded GPS levels in surface water. *Lack of positive trends in GW quality mean achievement of GPS is still yrs to decades away. GPS completion dates must be revised in the GW CAP.

27. Themes Affecting CA Effectiveness Observations from Virginia: MNA (the less expensive option) is not very effective in certain aquifer types (e.g., saprolite, fractured bedrock) likely due to insufficient microbe biology at depth to address the VOC mass or lack of available carbon in the aquifer matrix. LFs active in the 1960’s and 70’s were allowed to accept drummed solvent liquid wastes which readily entered the aquifer. Several LF plumes appear to still be expanding despite installation of low permeability cover in the 1990’s. This suggests maybe issues with cover installation or - was it really low permeability material(?). Base of plume (at depth) sometimes difficult to find (i.e., a lot deeper than you probably thought), meaning the size of the plume is larger than originally thought.

28. If Your Remedy Doesn’t Work- 9 VAC 20-81-260.G.2: An owner or operator or the director may determine, based on information developed after implementation of the remedy or other information contained in the evaluation, that compliance with requirements of subdivision H.1 of this section are not being achieved through the remedy selected. In such cases, the owner or operator shall implement other methods or techniques that could practicably achieve compliance with the requirements, unless the owner or operator makes the determination under subdivision G 3 of this section.

29. “Alternate Measures” Triggers? Under 9 VAC 20-81-260.G.2, it is a requirement that other methods or techniques be applied to achieve GPS on site if your first remedy choice has not been successful. The owner/operator has the responsibility to recognize when this action is needed, but if he/she doesn’t, the VSWMR give the director the authority to require it. If owner/operator requests it, it usually can be done under the Interim Measures provision for the first couple of years and not a formal Permit Modification to see if the alternate approach is going to work. DEQ will usually not make such decision until two CASE cycles have been completed, and/or an immediate risk to human health and the environment is recognized.

30. “Alternate Measures” Can Be- Brand new, site wide remedy replacing the original. An area specific, alternate remedy enhancement, to help the original remedy perform better. A one-time action (like an insitu enhancement) to ‘jump-start’ or accelerate the groundwater performance while keeping the original remedy.

31. Our Advice- Many MNA sites will be unable to achieve GPS unless assisted by some additional remedy or component. Don’t delay recognition of alternate remedy need, as cost associated with that, likely will mean cost reduction in the future if GPS are achieved sooner, rather than later. When possible DEQ will view such actions under the interim measures allowance, meaning no public notice and no Permit modification up front. Discuss any potential alternate remedy with your Regional Office early in the design process.

32. Our Advice- It’s better to be proactive rather than reactive when it comes to remediation!!

33. GW CA Questions/Concerns