September 29, 2026
Upper Occoquan Service Authority
14631 Compton Road
Centreville, VA 20121
Re: Comments on the Upcoming Renewal of the Industrial Wastewater Discharge Permit for Micron Technology, Inc. Virginia (Permit No. MAN006)
Dear Permitting Staff,
We, the undersigned organizations, urge the Upper Occoquan Service Authority (UOSA) and the City of Manassas to consider the following comments on the industrial wastewater discharge permit for Micron Technology, Inc. Virginia (Permit No. MAN006), located at 9600 Godwin Drive in Manassas, Virginia. Micron’s permit expires December 31, 2026. Although local pretreatment permits do not require a formal public notice or comment period, the UOSA is accepting comment from local stakeholders through September 30, 2026. Therefore, we are submitting these comments in advance, so they can be considered before the permit is renewed and finalized.
Semiconductors, also known as microchips, are used in everything from smart phones, electric vehicles, and computers to data centers and military defense systems. Semiconductor manufacturing, including companies like Micron, is known to be a significant discharger of per- and polyfluoroalkyl substances (PFAS).[1] PFAS are highly persistent, mobile in the environment, and build up in people and wildlife over time. These chemicals are extremely toxic even in very low concentrations and have been linked to serious health problems, including cancer, heart disease, and birth defects.[2],[3] When not treated at the source, these extremely toxic “forever” chemicals can pass through conventional wastewater treatment systems, and build up over time in human beings, wildlife, and the environment.
Micron sends its wastewater to UOSA. UOSA serves the northern half of Prince William County, a western portion of Fairfax County, and the entirety of the Cities of Manassas and Manassas Park. UOSA’s discharge flows via Bull Run to the Occoquan Reservoir, a major drinking water source for approximately two million people in Northern Virginia.[4] The UOSA has the duty to ensure that PFAS discharges are controlled and do not threaten the Occoquan Reservoir or nearby communities.
Communities in Virginia have been particularly attuned to and concerned about the local impacts from the rapid development of Artificial Intelligence (AI). The AI boom is driving a proliferation of semiconductor manufacturing facilities and data centers across the country. Semiconductor manufacturing is one example where the AI boom has led to an increase in the use and release of PFAS, underscoring the need to control these pollutants at the source.[5] Overall, as described below, the UOSA must use its existing authority to develop robust pretreatment requirements to control PFAS discharges from Micron.
Micron Must be Held Accountable for Its PFAS Pollution
According to Micron’s website, approximately half of all cars on the road today in the U.S. have a Micron chip made at its Manassas facility.[6] Micron estimates that, of total memory chips in the world, about 2% are manufactured at this facility.[7] In May 2026, Micron invested more than $2 billion in the expansion and modernization of its Manassas fab, which will quadruple Micron’s DDR4 wafer supply.[8] Given the expansive and growing scale of this facility, it is critical that the UOSA thoroughly plan for and manage PFAS discharges from this site using its existing authority under the Pretreatment Program.
The permit currently only requires quarterly monitoring using the Environmental Protection Agency’s (EPA’s) Method 1633, which tests for 40 PFAS compounds in wastewater. Clean Water Fund’s analysis of Micron’s wastewater monitoring data showed that 20 different PFAS compounds have been detected in Micron’s wastewater.[9] Micron had an average total PFAS concentration of 1,419 ng/L, based on 16 quarterly datasets received between 2022 and 2026. Perfluorobutanoic Acid (PFBA) represented the highest average concentration of PFAS at approximately 496 ng/L. In addition, Micron had an average concentration of 57 ng/L for Perfluorooctanoic acid (PFOA), more than 14 times the current federal drinking water Maximum Contaminant Level (MCL). Micron also had an average concentration of 32 ng/L for Perfluorononanoic acid (PFNA), more than 3 times the current MCL.
Approximately 68% of the total PFAS measured were short chain (4 to 6 carbon length) perfluoroalkyl carboxylic acids (PFCAs), which is consistent with industry trends replacing long-chain PFAS with short-chain alternatives. Short-chain PFAS chemicals are highly mobile in water and uniquely difficult to treat. None have been found to be safe to human health. But current monitoring likely understates the problem: studies have found that EPA’s Method 1633 detects less than 10% of the total organic fluorine of environmental concern.[10],[11],[12]
As demonstrated by the monitoring data, current pretreatment requirements are not adequately controlling PFAS wastewater discharges. The continued growth of manufacturing capacity at this facility coupled with high PFAS concentrations underscores the need for stronger PFAS controls.
UOSA has the authority to ensure that PFAS discharges are controlled and do not threaten the Occoquan Reservoir.
Publicly owned treatment works (POTWs) have existing permitting and pretreatment program authorities that can be used to address PFAS discharges. Under the pretreatment program, POTWs are given the authority to include permit conditions (like monitoring requirements, Best Management Practices [BMPs], effluent limits, etc.).[13] Such measures can be used for industrial permittees known or suspected of discharging PFAS.
Even though the UOSA plant employs advanced wastewater treatment processes, including granular activated carbon (GAC) adsorption,[14] GAC has been found to be less effective at removing short-chain alternatives. EPA’s “Review of Per- and Polyfluoroalkyl Substances (PFAS) in Industrial Wastewater Discharge” revealed one POTW using GAC achieved greater than 95 percent removal of PFOS, but only 40 to 70 percent removal of shorter-chain PFAS.[15] Since the semiconductor industry relies heavily on short-chain PFAS, they are likely to “pass through” UOSA’s GAC system. Therefore, stronger pretreatment standards are required to prevent PFAS from being discharged to UOSA and potential pass through. GAC also generates a concentrated residual waste containing high levels of PFAS that must be transported off-site for disposal.
Minimizing the use of PFAS and controlling PFAS discharges at the source ensures that this harmful pollution does not harm downstream communities, drinking water sources, or aquatic ecosystems. Overall, the UOSA must use its existing authority to develop robust pretreatment requirements.
UOSA must strengthen Micron’s pretreatment permit to prevent further PFAS contamination, safeguard drinking water sources, and protect nearby communities.
Because of the widespread use of PFAS and their highly toxic, persistent, and mobile characteristics, it is essential that UOSA monitor, minimize, and control PFAS pollution whenever the source is known.
The current permit falls short of addressing PFAS discharges from Micron. The permit’s lack of PFAS pollution limits and minimal monitoring requirements for PFAS are inadequate to protect water quality, the environment, and the health of workers as well as surrounding communities. Given the well-documented risks these chemicals pose to human health and the environment, it is imperative that UOSA holds Micron accountable for its PFAS discharges. Without such requirements, there is no assurance that PFAS discharges are being properly identified, monitored, or controlled.
We urge UOSA to consider the following recommendations prior to reissuing Micron’s pretreatment permit:
- 1. UOSA should require Micron to submit a PFAS Action and Minimization Plan.
- UOSA should require Micron to develop a PFAS Action and Minimization Plan as part of its pretreatment permit. The plan should require Micron to fully disclose all the PFAS that it uses, generates, or expects to be in its effluent. The plan should establish clear monitoring and reporting requirements. Micron should be required to describe minimization efforts, identify viable substitutions wherever feasible, and establish measurable reduction efforts. Micron should also be required to adopt treatment technologies necessary to eliminate PFAS discharges before discharge to UOSA. Such plans have been implemented by other POTWs, including Clean Water Services, which receives wastewater from seven different semiconductor manufacturing facilities near Portland, Oregon.
- 2. UOSA should require additional monitoring methodologies.
- PFAS monitoring is essential to understand the specific PFAS compounds present in Micron’s wastewater and to evaluate the effectiveness of its treatment processes. UOSA should revise the permit to require more robust wastewater monitoring methodologies. Given that there are thousands of types of PFAS, of which over one hundred are known to be used by the semiconductor industry, and new PFAS are constantly being introduced, testing for 40 compounds is inadequate for identifying the full suite of PFAS in semiconductor wastewater discharge. Studies have found that EPA Method 1633 detects less than 10% of the total organic fluorine of environmental concern.
- UOSA should consider additional wastewater monitoring requirements, beyond EPA Method 1633, to identify all PFAS present in Micron’s wastewater. For example, EPA Method 1621 is a standard analytical method for broadly testing organic fluorine in wastewater and can help provide context for what targeted analyses might miss. EPA has recommended supplementing Method 1633 with Method 1621.[16] For more information on additional monitoring methodologies, see CHIPS Communities United’s detailed comments submitted on the Analog Devices industrial user permit located in Camas, Washington.
- 3. UOSA should ensure adherence to the Occoquan Reservoir PFAS Reduction Program.
In 2025, HB 2050 created the Occoquan Reservoir PFAS Reduction Program to reduce excessive levels of PFAS in public drinking water from the Occoquan Reservoir.[17] The program requires applicable discharge permits to be modified when monitoring data shows that PFAS concentrations have exceeded drinking-water MCLs.[18] The bill requires the modified permit to provide a compliance schedule that requires compliance with such level as soon as possible but no later than July 1, 2029. Micron’s monitoring data exceeds the MCLs for both PFOA and PFNA. Therefore, UOSA should modify Micron’s pretreatment permit to require the facility’s discharge not exceed the MCLs.
- 4. UOSA should, at minimum, incorporate numeric limits for PFAS discharges that are at least as stringent as the promulgated MCLs.
- Under the existing permit, Micron should not discharge any pollutant which can cause pass-through, constitute a hazard to humans or animals, or create a toxic effect in the receiving waters of the POTW.[19] In addition, Micron should not discharge any substance that will cause the POTW to violate its VPDES permit or the receiving water quality standards.[20] Therefore, in order to comply with these requirements and those of the Occoquan Reservoir, UOSA should establish PFAS limits in Micron’s permit. These limits could include, but are not limited to, the drinking water MCLs for PFAS and any other numeric limits necessary to assure compliance with current narrative water quality standards and prospective numeric criteria for the Bull Run and other receiving waterways.
- 5. UOSA should encourage that Micron use the most advanced technologies to eliminate PFAS at the source.
- It is especially important to control PFAS at point sources such as Micron. While other industries are already being regulated with PFAS restrictions and bans, the semiconductor industry claims that PFAS are essential throughout the fabrication process. As semiconductor production continues to grow and evolve, the industry should be required to use the most advanced technologies to eliminate PFAS at the source.
- GAC and reverse osmosis do not destroy PFAS and instead generate a concentrate containing high levels of PFAS that must be transported off-site for disposal. This concentrated waste stream poses numerous environmental and public health concerns. A growing variety of technologies exist which are capable of destroying PFAS.[21] Industrial dischargers of PFAS-containing wastewater, such as Micron, should be required to use treatment methods that use the most advanced technologies to eliminate PFAS at the source.
- 6. UOSA should establish a goal of zero discharge of PFAS.
- Managing PFAS through limits for one chemical at a time will take years, delay critical protections, and may encourage the creation of alternatives that are just as harmful to skirt around protections. Given the persistent, bioaccumulative, and toxic nature of PFAS, UOSA should require a zero-discharge goal for PFAS from all industrial uses. For example, Micron in Boise, Idaho is building a zero liquid discharge facility.[22] Every additional release of PFAS builds up in the local, regional and global environment, leading to contamination of drinking water supplies, fish, wildlife, livestock, and in humans.
- 7. UOSA should require public reporting of monitoring results to ensure transparency and accountability.
- Public access to monitoring data ensures transparency, accountability, and public trust. UOSA should require monitoring data be reported and posted to an easily accessible public website within 30 days of collection. Timely posting will build public trust in the effectiveness of minimization and treatment efforts and allow for the early detection of emerging issues.
Overall, UOSA must use its existing authority to hold Micron accountable for its PFAS pollution by strengthening PFAS monitoring, reporting, and treatment requirements within its industrial wastewater discharge permit. Our communities cannot afford to wait for the federal government to finalize new requirements and regulations to address PFAS discharges. None of these proposed recommendations would prevent Micron from continuing to produce chips. By addressing these concerns, UOSA will hold industry accountable for its known wastewater discharges and help to protect nearby communities and the Occoquan Reservoir from further PFAS contamination.
Sincerely,
Julie MacNamara
Clean Water Action and Clean Water Fund
Judith Barish
CHIPS Communities United
Lenny Siegel
Center for Public Environmental Oversight
Mike Belliveau
Bend the Curve
Anna Smith
Jobs to Move America
David Flores
Potomac Riverkeeper Network
Jennifer Cole
Clean Fairfax
Stewart Schwartz
Coalition for Smarter Growth
David Reed
Chesapeake Legal Alliance
Ken Wright
Potomac Conservancy
Matt Henjum
Waterkeepers Chesapeake
David Sligh
Wild Virginia
Carroll Courtenay
Southern Environmental Law Center
Renee Grebe
Nature Forward
Dan Shaffer
Allegheny-Blue Ridge Alliance (ABRA)
[1] National Institute of Standards and Technology, Final Programmatic Environmental Assessment for Modernization and Expansion of Existing Semiconductor Fabrication Facilities under the CHIPS Incentives Program (June 28, 2024), https://www.nist.gov/system/files/documents/2024/06/28/Final%20PEA%20for%20Modernization%20and%20Expansion%20of%20Semiconductor%20Fabs%206-28-2024%20-%20OGC-508C.pdf (Table C-4)
[2] EPA, Our Current Understanding of the Human Health and Environmental Risks of PFAS,
https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks
[3] CDC, How PFAS Impacts Your Health, https://www.atsdr.cdc.gov/pfas/about/health-effects.html?CDC_AAref_Val=https://www.atsdr.cdc.gov/pfas/health-effects/index.html
[4] UOSA, “2024 Annual Comprehensive Financial Report” https://uosa.org/wp-content/uploads/2024/12/UOSA_ACFR_2024_r17-hrz-FINAL.pdf
[5] Environmental Health News, “PFAS pollution risk grows as chemical companies ramp up production for AI chip demand” (June 13, 2025). https://www.ehn.org/pfas-pollution-risk-grows-as-chemical-companies-ramp-up-production-for-ai-chip-demand
[6] Micron, “Micron in Manassas, Virginia” https://www.micron.com/us-expansion/va (Accessed September 2, 2026).
[7] Micron, “Micron in Manassas, Virginia” https://www.micron.com/us-expansion/va (Accessed September 2, 2026).
[8] Micron, “Micron Advances Made-in-America Memory With Manufacturing Expansion in Virginia” https://investors.micron.com/news/press-release/2026/Micron-Advances-Made-in-America-Memory-With-Manufacturing-Expansion-in-Virginia/default.aspx
[9] Clean Water Fund requested Micron’s monitoring data via public records request through the Upper Occoquan Service Authority FOIA Office. The data were received on April 23, 2026.
[10] Shelor, C. P.; Warren, C.; Odinaka, C. V.; Dumre, K. Comprehensive review of combustion ion chromatography for the analysis of total, adsorbable, and extractable organic fluorine. J. Sep.Sci. 2024, 47 (15), 2400235.
[11] Ersan, M. S.; WangWongWesterhoff, B. M. S. P.; Westerhoff, P. Advanced oxidation processes may transform unknown PFAS in groundwater into known products. Chemosphere 2024, 349, 140865.
[12] Schultes, L.; Vestergren, R.; Volkova, K.; Westberg, E.; Jacobson, T.; Benskin, J. P. Per- and polyfluoroalkyl substances and fluorine mass balance in cosmetic products from the Swedish market: implications for environmental emissions and human exposure. Environ. Sci. Process. Impacts 2018, 20 (12), 1680−1690.
[13] 40 CFR 403.8(f)(1)(iii)
[14] UOSA, “Water Treatment” https://uosa.org/water-treatment/ (Accessed September 4, 2026).
[15] EPA, “Review of Per- and Polyfluoroalkyl Substances (PFAS) in Industrial Wastewater Discharge” (October 2019). https://www.regulations.gov/document/EPA-HQ-OW-2021-0547-0359 (pg 6-1).
[16] EPA, ”Methods Update Rules,” https://www.epa.gov/cwa-methods/methods-update-rules”; EPA, ”Addressing PFAS Discharges in NPDES Permits and Through the Pretreatment Program and Monitoring Programs“ (Dec. 2022); EPA, “Addressing PFAS Discharges in EPA-Issued NPDES Permits and Expectations Where EPA is the Pretreatment Control Authority“ (April 2022). https://www.epa.gov/system/files/documents/2022-04/npdes_pfas-memo.pdf
[17] Virginia Department of Environmental Quality, Per- and Polyfluoroalkyl Substances (PFAS), https://www.deq.virginia.gov/news-info/shortcuts/topics-of-interest/per-and-polyfluoroalkyl-substances-pfas (Accessed September 4, 2026).
[18] HB2050 https://lis.virginia.gov/bill-details/20251/HB2050
[19] Industrial Wastewater Discharge Permit for Micron Technology, Inc. Virginia (Permit No. MAN006) Section B (1) (D).
[20] Industrial Wastewater Discharge Permit for Micron Technology, Inc. Virginia (Permit No. MAN006) Section B (1) (G).
[21] A. Reese, Waste Dive, “U.S. Department of Defense-funded PFAS demo projects show promise for remediation and destruction” (Dec. 1, 2025). https://www.wastedive.com/news/dod-pfas-destruction-disposal-demos-waste/805991/; B. Erikson, Chem & Eng, News, “Competition to destroy ‘forever chemicals’ heats up” (Mar. 4, 2024) https://cen.acs.org/environment/persistent-pollutants/Competition-destroy-forever-chemicals-heats/102/i7
[22] ‘Hard to make that decision’: City of Boise pauses water recycling facility project. (June 2, 2026) https://www.ktvb.com/article/news/local/city-indefinitely-pauses-first-recycled-water-facility-southeast-boise/277-21c8fc02-f81e-41eb-a34a-dadffca7c97b
