The Lawrence Livermore National Laboratory (LLNL) has been cleaning up volatile organic compounds (VOCs) in groundwater for over three decades, and the 2024 Annual Report shows steady but gradual progress. In 2024, the cleanup efforts removed about 31.3 kilograms of VOCs (approximately 69 pounds) from soil and groundwater. This brings the cumulative total to roughly 3,574 kg of VOCs (~3.9 tons) removed since remediation began in 1989. Some of the toxic solvent plumes beneath the site have shrunk in concentration and area over time, and LLNL reports ongoing declines in VOC levels across most areas. The lab has maintained hydraulic containment of the pollution, meaning the on-site plumes are not spreading beyond the site’s borders. However, while the overall trend is positive, the report notes that declines in some areas were “subtle”, indicating that as the cleanup progresses, it’s getting harder to wring out the remaining contamination. After decades of remediation, we’re in the stage of diminishing returns. Much of the easy-to-remove pollution is gone, and what’s left tends to be stuck in soil pores or bedrock, releasing slowly. This means that without additional intervention, it could take a long time for those last pockets of VOCs to dissipate. The key point for the community is that groundwater VOC levels are generally going down, not up, and containment is working. But until all parts of the plume are below cleanup standards, the job isn’t finished – a reality the lab could do more to recognize.
Treatment Facilities: Operations and Mass Removal in 2024
In 2024, 25 groundwater treatment facilities and 7 soil vapor treatment facilities were in operation. These facilities collectively draw contaminated groundwater and soil vapor out of the ground for treatment. However, the volume of VOC mass being removed each year is tapering off as concentrations fall. This highlights the importance of attacking the source areas of contamination more directly using new methods, rather than relying only on decades of pump-and-treat to eventually do the trick. The marginal 31 kg removed in 2024 represents less than 1% of the total mass removed to date, highlighting how much the removal rate has tapered off as the easier, high-concentration mass was extracted in earlier years.
The data shows that the cleanup system is removing less and less pollution over time — it’s slowing down. This is expected because as pollution levels get closer to the cleanup goals, the system (called “pump-and-treat”) becomes less effective, especially in parts of the ground that water doesn’t flow through easily. The report even says that some changes in pollution levels from year to year can’t be explained just by the cleanup efforts, which suggests that pollution is still trapped in harder-to-reach areas underground. This is a known issue with the pump-and-treat method.
The system is still doing its job of keeping pollution from spreading, but it might take a long time, possibly decades, to fully clean some areas unless new methods are added. The report doesn’t say when all the groundwater will be safe to drink, and that’s a gap in the planning. It would be more helpful if they included updated predictions and checked whether they’re still on track to meet their original cleanup goals.
The report also says the system is capturing all the pollution (hydraulic capture), but it doesn’t provide enough hard evidence to prove it. While it mentions some maps that show water flow, it doesn’t include detailed analysis that would confirm pollution is fully contained, especially at the outer edges of the plume.
In short: the system is still working, but not as well as before. That’s why it’s important to both improve the current setup and try new strategies (like the ESAR pilot tests) to speed up the cleanup in tough spots.
Enhanced Source Area Remediation (ESAR) Pilot Projects
LLNL is testing new cleanup methods at a few of the most polluted spots to speed things up — just using the regular “pump-and-treat” system isn’t enough anymore. These extra methods are part of what they call Enhanced Source Area Remediation (ESAR). According to the 2024 Annual Report, they’re trying out three pilot projects:
- At the TFD Helipad site: They’re using a method called in situ bioremediation, which basically means they’re adding helpful bacteria or nutrients directly into the ground to break down pollution naturally.
- At the TFC Hotspot site: They’re using zero-valent iron, which is a type of iron that helps trigger chemical reactions underground to clean up the pollution.
- At the TFE Eastern Landing Mat site: They’re trying thermally-enhanced extraction, which involves heating up the ground to make it easier to suck out the remaining contaminants.
We examine each below, focusing on effectiveness, data trends, and any limitations or reporting clarity issues.
- TFD-HPD In Situ Bioremediation (Lactate/Bioaugmentation):
At the Helipad site (TFD-HPD), LLNL is testing a cleanup method that uses bacteria and chemicals injected underground to break down toxic chemicals like TCE and carbon tetrachloride. This method works best in oxygen-free (anaerobic) environments, so they’re adding lactate (a food source for bacteria) and a specialized mix of bacteria (KB-1®) to help speed up this natural breakdown process.
In 2024, they were able to keep the underground conditions right for the bacteria to do their job. Some monitoring wells show a clear drop in contamination levels:
- Well W-3702 dropped from 3,000 to 1,600 µg/L of TCE — nearly 50% less in a year.
- Well W-3703 dropped from 1,300 to 1,000 µg/L.
The main report doesn’t directly mention these results. You have to dig into Appendix C to see the numbers. This makes it harder to understand the full impact unless you read the fine print. Also, it is important to note that not all wells improved—one well (W-1253) actually got worse, and others bounced around without a clear pattern. That suggests the cleanup might not be working evenly across the area.
The results could be mixed because the soil underground isn’t uniform. Some areas are easier to treat than others. There could also be “rebound” effects, where pollution comes back temporarily between treatment cycles. It’s also tricky to get the injected materials to spread out evenly in lower-permeability areas. The pilot program will continue into 2025, since it’s still unclear whether this method will fully clean up the area long-term.
- TFC Hotspot In Situ ZVI Treatment:
At the TFC Hotspot, LLNL is testing a chemical cleanup method where they inject zero-valent iron (ZVI) into the ground. The idea is that this iron reacts with toxic chemicals like TCE and breaks them down underground, without needing to pump the water out first. In 2024, the monitoring data showed that the chemical reactions triggered by ZVI were still happening, the groundwater near the treatment zones continued to show signs of those reactions, like higher iron levels and other byproducts. That’s a good sign that the ZVI is still active nearly a decade after it was placed.
Some of the wells near the ZVI panels have seen large drops in TCE over time. For example, one well dropped by 74%, another by 51%, and a third hit a low point early in 2024 and climbed back up later in the year. That rebound is concerning. While the report says it might just be a short-term fluctuation, it raises questions about how stable the treatment really is. It’s encouraging that even the “rebounded” levels are still much lower than they were before ZVI was installed, but it’s too soon to say whether this method is keeping contamination down for good.
A major issue here is that the soil underground is patchy, some parts are more absorbent than others. That makes it hard for the ZVI to reach every part of the contaminated area. In fact, the data shows that while the zones directly next to the ZVI panels are cleaning up well, contamination in areas just above or below hasn’t improved as much. One deeper well only saw a 36% drop in TCE, far less than what was seen closer to the iron. This shows a key limitation: ZVI has a limited reach, and pollution that’s just outside its influence can linger for years.
While it’s reassuring that the treatment hasn’t caused any major side effects like metal leaching or gas buildup, the fact that this pilot is still ongoing into 2025 suggests LLNL hasn’t yet proven this approach is a long-term fix. It works in places—but not everywhere—and the patchy results mean further improvements and better planning will be needed before this can be considered a fully successful cleanup strategy.
- TFE-ELM Thermally Enhanced Remediation:
The thermal cleanup pilot at the Eastern Landing Mat (TFE-ELM) was essentially a failure in 2024. Unlike the other two test sites, nothing actually happened here this past year—because the system broke down. The method LLNL chose (likely electrical heating of the soil and groundwater to help pull out contamination) ran into a major technical problem: the heat caused minerals in the groundwater to build up and clog the wells, making them unusable. This is a known risk with thermal remediation, but it seems LLNL didn’t anticipate just how bad the scaling would be in this area. As a result, the entire system was shut down all year.
LLNL says they’re still figuring out how to fix the wells and restart the system, but so far, there’s no clear plan or timeline, and it’s not obvious whether the method can even be salvaged. In the meantime, no real cleanup has occurred at this site, other than the bare minimum from existing pump-and-treat systems. That means the contamination in this area has likely stayed the same, or even gotten worse, while other areas moved forward with treatment.
This is a major setback for the overall Enhanced Source Area Remediation (ESAR) program. One of the three pilot projects has completely stalled, with no backup strategy in place. While the report does acknowledge the failure and mentions that LLNL is looking into solutions, it lacks transparency about next steps. There’s no clear explanation of when this will be fixed, or even whether it’s still worth pursuing.
Tri-Valley CAREs should press hard on this issue—it’s unacceptable for an entire source zone to be left untreated for over a year with no clear path forward. At minimum, the community deserves clarity about whether the thermal system will be repaired, replaced, or abandoned—and what LLNL will do instead to protect public health and clean up this site.
Tritium and Chromium Monitoring Data
In addition to VOCs, the Livermore Site groundwater contains radiological and inorganic contaminants that merit close scrutiny, notably tritium (radioactive hydrogen, a β-emitter with a half-life of ~12.3 years) and chromium (a heavy metal, monitored here as total chromium).
Tritium, a radioactive form of hydrogen from past weapons work at LLNL, is still lingering in the groundwater at a few key spots on site, especially near the old Building 419, Building 292, and a former trailer area. While LLNL claims that tritium has decayed significantly in most of the groundwater plume, a closer look at the data tells a more complicated and concerning story. In several wells near Building 419, tritium levels are not only still above the legal safety limit (20,000 pCi/L), they actually increased in 2024. One monitoring well, W-1414, has now exceeded that standard for six straight years, rising to over 37,000 pCi/L last summer and holding steady near that level. Another well in the same area spiked to nearly 36,000 pCi/L. These are not small fluctuations; they show a clear failure to contain or significantly reduce the contamination at its core.
LLNL attributes these spikes to heavy rainfall in 2023 that raised the groundwater table and mobilized tritium from shallower zones. But this explanation, though plausible, feels like a convenient excuse. This same rebound effect has happened before, and yet no proactive measures were put in place to prevent it. Instead, LLNL continues to rely on a passive strategy of “monitored natural attenuation,” essentially just watching and waiting for the tritium to decay on its own over time. That sounds fine in theory, since tritium does eventually break down, but in practice, it means LLNL is depending on nature to do the cleanup for them, over decades.
The data also shows inconsistency. Some wells further away from the source show low or no tritium, which suggests the plume isn’t expanding significantly right now. But even within that “good news,” there are odd results, like well W-3902, which jumped from barely detectable to over 8,000 pCi/L in just a few months. That kind of variation should raise serious questions about how stable the plume really is and whether LLNL is doing enough to understand what’s happening underground.
The report is transparent about these issues. But transparency alone isn’t enough. There’s no clear plan to deal with the areas where tritium levels are stuck or rising. There’s no discussion of alternative approaches or even contingency planning if levels don’t drop as predicted. And while tritium may not pose an immediate risk, since the contaminated groundwater isn’t used for drinking, that doesn’t completely justify the current “do-nothing and monitor” stance. Contamination this persistent demands more than just well sampling every few months.
If this trend continues, Tri-Valley CAREs should insist on stronger commitments from LLNL: clearer remediation goals, backup plans if concentrations don’t drop, and more robust monitoring of both horizontal spread and vertical layers of the plume. Relying on radioactive decay alone, with no additional safeguards, is stalling the cleanup.
Vapor Intrusion and Indoor Air: Ensuring Safe Breathing Space
Figure 1: Estimated total VOC mass removed from groundwater at the Livermore Site since 1989
One big concern when it comes to community health is indoor air pollution caused by vapor intrusion. This happens when toxic chemicals that have spilled or leaked into the ground, especially industrial solvents like TCE (trichloroethene) and PCE (perchloroethene), start to rise up through the soil as gas. These vapors can seep into buildings from underground and potentially harm people who live or work inside.
In 2024, the lab tested indoor air in 12 buildings at the Livermore Site as part of its ongoing monitoring program. These buildings were chosen because they had previously shown harmful chemicals (TCE or PCE) in the air. Five buildings were removed from the program after two years of clean results, and one old trailer was taken off the list because it was demolished. The 12 buildings tested this year are the ones that are still considered a concern. The sampling was thorough. The team collected 87 indoor air samples from places inside the buildings, including rooms, crawl spaces, utility areas, and other spots where vapors might enter. They also took 13 outdoor air samples to compare. Sampling areas like crawl spaces helps check if harmful vapors are building up around or beneath a building, even if they haven’t reached the main indoor air yet.
TCE or PCE was found in 6 out of the 12 buildings tested, but none of the levels were high enough to exceed health-based screening limits. These limits are set to flag potential long-term health risks like cancer. Since none were exceeded, the report concludes that vapor intrusion is currently under control and not posing an immediate risk, as long as the vapor treatment systems stay on. If those systems were shut down, the situation could change.
Right now, the data show that workers inside the monitored LLNL buildings are not being exposed to harmful levels of VOCs. This is true as long as two things stay the same:
- the air samples reflect real indoor conditions, and
- the vapor treatment systems keep running.
LLNL is doing a good job of testing during worst-case conditions (like winter) and checking crawl spaces and other potential entry points. The seven vapor extraction systems on-site are also helping keep pollution levels low.
As for the general public, the report focuses on buildings within LLNL. Off-site areas, like nearby neighborhoods, aren’t mentioned, likely because past reviews found little risk there. The main off-site pollution plume heads west, but it’s being captured by systems along the site’s edge. Since groundwater is deeper and pollution levels are lower off-site, vapor intrusion hasn’t been flagged as a big concern. On-site, most buildings are labs or offices, and risks are being managed through monitoring and cleanup. When buildings show no contamination over time, they’re removed from the program, a good sign that cleanup efforts are working.
One concern for the future is what happens when LLNL shuts down its cleanup systems. The report says the air is safe while these systems are running, but once groundwater cleanup is done, LLNL may want to turn them off. Before that happens, they’ll need to prove it won’t cause new vapor intrusion problems. Tri-Valley CAREs should push for a solid exit plan, including air monitoring even after cleanup ends.
Also, more transparency would help. The report says no buildings went over safety limits, but doesn’t say how close any of them got. Were the levels just barely detectable, or were some close to the health threshold? If any buildings were near those limits, it might call for more attention, like adding ventilation. Since no extra actions were mentioned, it seems all the readings were well below concern, but clearer info would help the public understand the risk.
To stay accountable, LLNL should keep reporting results every year and alert the public right away if any harmful levels are found. Tri-Valley CAREs may want to ask that all data stay available and that testing continues until buildings show no contamination over time or the area beneath them is proven clean. Even buildings removed from regular testing should still be checked every few years, just in case something changes, like rising groundwater pollution or a new use for the building.
Impacts of the 2024 Budget Shortfall on Cleanup Progress
One of the most troubling points in the 2024 Annual Report is that budget cuts delayed key cleanup work. The report admits that because of limited funding, no drilling related to the CERCLA cleanup happened in 2024, and fewer upgrades were made to treatment systems. This means some important work was postponed. From a technical oversight standpoint, this raises concerns about missing data now and slower progress on long-term cleanup goals.
Drilling is a key part of the cleanup process because it allows for installing new monitoring or extraction wells when needed. But in 2024, no drilling was done due to budget cuts. That means any planned wells, like ones needed to better track pollution plumes, weren’t installed. For example, if previous data showed the need for a new well to check the edge of a tritium or VOC plume, that work is now delayed. Luckily, two wells (W-3902 and W-3903) were added in 2023 before the funding issues hit. Still, any follow-up drilling or extra extraction wells needed in 2024 didn’t happen, which could slow cleanup and leave gaps in data. This is a concern, especially since some areas are cleaning up slowly and often need new wells to help move things along.
The report shows that only limited upgrades were made to the treatment systems in 2024 because of budget cuts. These upgrades usually involve replacing old parts, improving performance, or adjusting systems to deal with changing conditions like drought. Delaying this work means the project is relying on aging equipment longer, which could impact reliability. One change mentioned was combining two systems, TFC-East and TFD-WTC, to cut costs by operating fewer facilities. While streamlining can help with efficiency, it shouldn’t reduce the system’s overall effectiveness. Tri-Valley CAREs may want to ask whether cost-saving moves like this reduce backup capacity. If fewer systems are running, even a small failure could affect cleanup. While no failures were reported in 2024, delays in upgrades might mean there’s less safety margin going forward.
Under CERCLA, DOE and LLNL are required to keep the cleanup protective, and budget cuts don’t excuse skipping critical monitoring or containment work. If major tasks like drilling were delayed, the EPA and state agencies (DTSC and the Water Board) should have been notified. The report’s compliance section should show whether all required actions were completed. The fact that no drilling happened in 2024 is a serious deviation from normal progress. If those wells were part of a work plan or cleanup recommendation, skipping them may be a compliance issue that needs to be fixed as soon as funding is available.
It’s important to ask whether the 2024 funding shortfall was a one-time problem or part of a larger trend. If it was just for one year, the project might catch up later. But if tight budgets continue, cleanup work could be delayed again and again. Tri-Valley CAREs should keep in mind that cleanups at federal sites like LLNL often depend on uncertain funding. That’s why community advocacy is key, especially to push for steady support and keep cleanup efforts moving forward. This year shows what can happen when funding falls short: critical work gets postponed, and the long-term safety of the site could be at risk if it keeps happening. Tri-Valley CAREs may want to raise this concern in public meetings and with DOE leadership to push for stable, long-term funding for the LLNL cleanup.
Regulatory Compliance and Oversight Considerations
The Annual Report shows that DOE/LLNL followed required cleanup rules under CERCLA and stayed on schedule with their reports to regulators. Key documents, like the 2023 Annual Report and quarterly monitoring updates, were submitted on time in 2024. The included appendix shows that they also followed land use rules that keep people from using contaminated areas improperly. There’s no sign that LLNL broke any permit limits or discharge rules, for example, treated water from cleanup systems likely stayed within allowed levels. If there had been any problems, the report would likely have mentioned them.
The Fifth Five-Year Review (with an update in 2021) called for ongoing vapor intrusion monitoring, which LLNL has been doing. The next full review is expected in 2025 or 2026. It will be important for that review to look closely at how the 2024 funding shortfall affected cleanup progress and whether the project is still on track. Tri-Valley CAREs should take part in that process to make sure community concerns, like delays, high contamination levels, or the need for more cleanup, are raised and addressed. Any big changes to the cleanup plan, like expanding new treatment technologies, would likely be considered during that review.
The ultimate cleanup goal is to bring groundwater pollution down to safe drinking water levels, like 5 µg/L for TCE and 20,000 pCi/L for tritium. The report shows some spots still above those limits. Under CERCLA, cleanup can still be considered “protective” as long as people aren’t being exposed, even if those final targets haven’t been met yet. This is called “interim protectiveness.” Right now, LLNL appears to be meeting that standard, but full cleanup is still a work in progress. If pollution levels stop going down, regulators may require LLNL to take new actions. The report’s mention of ESAR is a good sign that LLNL is trying to speed things up. Still, if pump-and-treat stops being effective in some areas, regulators should either push for more aggressive cleanup or officially shift to a long-term monitoring approach with land use controls.
Another suggestion is that LLNL should keep sharing raw monitoring data, ideally through an online portal. This would enable outside experts to review it too. TEIMS, LLNL’s database for sampling results, seems comprehensive, and giving Tri-Valley CAREs access to it could support independent oversight.
The Annual Report is one of the main ways LLNL communicates with the public and regulators, but it’s very technical. Tri-Valley CAREs helps by reviewing and explaining it for the community. It would help if LLNL also shared a simpler summary, like a fact sheet or public presentation. Topics like budget shortfalls and how they plan to address them should also be discussed openly in those public meetings.
Recommendations
Based on the above critique of the 2024 Annual Report, the following recommendations are offered to strengthen cleanup oversight, improve performance tracking, and enhance public accountability:
- Catch Up on Delayed Work: LLNL should focus on finishing the cleanup tasks delayed in 2024 as soon as possible in 2025. This includes installing any wells that weren’t drilled and completing postponed upgrades to treatment systems. Regulators should get a clear schedule to track when this work will be done and make sure no important data is missed.
- Ensure Reliable Cleanup Funding: LLNL and DOE must secure steady funding to avoid future delays in the Groundwater Project. Tri-Valley CAREs and local groups should push for full funding through DOE and Congress. Cleanup progress and public safety shouldn’t be affected by budget cuts. DOE should clearly explain how they’ll fix the 2024 funding gap and prevent it from happening again.
- Make ESAR Reporting Clearer: The Annual Report should better explain how the ESAR pilot projects are doing. A simple graph showing pollution levels over time and how much they’ve gone down would help. LLNL should also share clear goals for these projects, like how much pollution needs to be removed to expand the technology, and what happens if a pilot isn’t working. This will help Tri-Valley CAREs and regulators track progress and push for successful solutions to be used more widely.
- Keep and Expand Vapor Intrusion Monitoring: Annual indoor air testing should continue in all buildings where contamination was found, even if levels are low. A building should only be removed from testing after several clean results in a row. Even then, spot checks every few years, or if groundwater conditions change, are recommended to stay safe. Before shutting down any vapor cleanup systems, a full review (like extra air tests or a rebound test) should confirm the air will remain clean. All data and risk info should be shared with workers and the community. If future tests show pollution getting close to risky levels, DOE/LLNL should act early, like adding ventilation or sealing cracks, rather than waiting for a problem.
- Tackle Persistent Hotspots (VOC and Tritium): For areas where VOC pollution isn’t going down much, DOE/LLNL should try new cleanup methods, like expanding ESAR treatments or adjusting how they pump out contamination. For tritium hotspots, active cleanup may be tough, but DOE should consider whether containing the most polluted areas with extra pumping could help. Right now, tritium is just left to break down over time, but if models show it could stay above safe levels for decades, DOE should look into faster cleanup options. At the very least, tritium levels should be tested often to track any changes. Tri-Valley CAREs may also ask for a special study on the old B419 tritium plume to explore more solutions.
- Language Access: Throughout the report, there’s a pattern of minimizing language. Issues like stalled cleanup progress, pilot test setbacks, and even a full-year budget shortfall are described in vague or softened terms. This kind of framing makes it harder for the public to understand what’s really going on, and for impacted communities to hold the lab accountable. For a site dealing with toxic and radioactive waste, full honesty matters.
- Strengthen Oversight: EPA, DTSC, and the Water Board should keep a close watch on DOE/LLNL’s progress and hold them to enforceable cleanup goals. Because this is a long-term project, it would help to set performance targets every few years and not just rely on yearly reports. If those targets aren’t met, backup plans should be ready. The upcoming Five-Year Review is a chance to see if the current cleanup plan is still the best option and whether successful pilot technologies should be added. Tri-Valley CAREs should plan to submit community comments, highlighting the concerns shared in this memo.
By implementing these recommendations, LLNL can improve the effectiveness of the cleanup effort and maintain the trust and safety of the surrounding community. Tri-Valley CAREs, as the community’s technical watchdog, will continue to monitor LLNL’s progress and advocate for a thorough, timely, and protective cleanup of the Livermore Site groundwater.