Proposed changes to the U.S. Environmental Protection Agency (U.S. EPA) CCR Rules in 40 CFR 257 (Federal Register/Vol. 83, No. 51/Thursday, March 15, 2018/Proposed Rules) could have a significant impact on coal-fired power plants, especially with regard to groundwater monitoring requirements and close-in-place capping.
BACKGROUND AND KEY POINTS
- The rule changes are proposed in response to
- Judicial Remand, April 18, 2016, resolution of Utility Solid Waste Activity Group (USWAG) et al. v. U.S. EPA no. 15-1219, D.C. Circuit Court); and
- The Water Infrastructure Improvements for the Nation (WIIN) Act enacted in December 2016.
- Additional proposed rule changes are in response to comments to U.S. EPA received after the final CCR rule date.
- Proposed rules address four provisions of the final rule that were remanded on June 14, 2016.
- U.S. EPA presently intends to take final action on proposed rule amendments in response to Judicial Remand by June 2019.
- U.S. EPA also proposes seven provisions that establish alternative performance standards for CCR units located in states that have approved CCR permit programs (identified as “participating states,” such as Oklahoma) under the WIIN Act.
- If not in a participating state, U.S. EPA will administer a permit program for CCR units.
- Also, additional proposed changes effect record keeping, notification, and internet posting requirements.
- U.S. EPA is not considering any other comments on other provisions of the final CCR rule under this specific proposal; however, additional revisions may be changed subject to challenge in litigation.
- The comment period for the proposed CCR rule amendments ended on April 30, 2018.
These proposed actions are estimated to result in net cost savings of between $25 million and $76 million per year for the industry. Cost savings are attributable to the proposed amendments against the baseline costs of the 2015 CCR rule.
SUMMARY OF THE U.S. EPA PROPOSED AMENDMENTS
Proposals Associated with Judicial Remand
Four proposed changes:
- Add boron to the list of Appendix IV parameters that trigger corrective action and potentially require CCR unit retrofit or closure.
(Read more detail here)
- Determine the requirement for woody and grass vegetation for slope protection.
(Read more detail here)
- Clarify the type and magnitude of non-groundwater releases requiring facilities to comply with some or all of the corrective action procedures in 40 CFR 257.96-257.98 for cleanup of the release. U.S. EPA is proposing a subset of corrective action procedures for non-groundwater releases that can be completely remediated within 180 days from detection of the release.
(Read more detail here)
- Modification of the alternative closure provisions to allow management of both CCR and non-CCR waste streams under exception for a certified absence of alternate disposal capacity.
(Read more detail here)
Proposals Associated with the WIIN Act
General proposed provisions:
- U.S. EPA is seeking comments on how alternative performance standards can be implemented directly by the facilities, even in states without a permit program, given that U.S. EPA has oversight and enforcement authority.
- U.S. EPA seeks comment on whether to allow participating states the ability to modify the location restrictions on a site-specific basis, and whether changes to the location restriction deadlines are appropriate.
Seven alternative performance standards:
- Allow the use of risk-based groundwater protection standards for Appendix IV constituents with no MCL.
(Read more detail here)
- Allow modification of the corrective action remedy in certain cases.
(Read more detail here)
- Allow the suspension of groundwater monitoring if a no-migration demonstration can be made.
(Read more detail here)
- Establish an alternate schedule to demonstrate compliance with the corrective action remedy.
(Read more detail here)
- Modify the post-closure care period.
(Read more detail here)
- Allow Director of participating states to issue technical certifications, rather than the current certifying engineer requirement.
(Read more detail here)
- Allow the use of CCR during certain closure situations.
(Read more detail here)
If you have questions about any of the above-mentioned details regarding U.S. EPA’s proposed changes to the CCR Rules, please contact one of the blog post authors: Roy Stanley, C.P.G., in our Columbus office (email@example.com; 888-598-6808 ext. 3316) or Brianne Hastings, P.G., in our Pittsburgh office (firstname.lastname@example.org; 800-365-2324 ext. 1117). More information on the proposed changes can be found at the links placed within this post, or by visiting U.S. EPA’s website at https://www.epa.gov/coalash/coal-ash-rule.
Requirements for the Final TSCA Inventory Notification (Active/Inactive) Rule – (40 CFR Part 710), published August 11, 2017
On June 22, 2016, the Frank R. Lautenberg Chemical Safety for the 21st Century Act, which amends the Toxic Substances Control Act (TSCA), was signed into law, making it the nation’s new primary chemicals management law.
According to the EPA, the new law, which received bipartisan support in both the U.S. House of Representatives and the U.S. Senate, includes much needed improvements such as:
- Mandatory requirement for EPA to evaluate existing chemicals with clear and enforceable deadlines;
- New risk-based safety standard;
- Increased public transparency for chemical information; and
- Consistent source of funding for EPA to carry out the responsibilities under the new law.
One year later, on June 22, 2017, EPA announced the required implementation activities. Those activities included finalization of a rule to require industry to report chemicals manufactured, imported, or processed in the U.S. over the past 10 years. This reporting will be used to identify which chemical substances on the TSCA Inventory are active in U.S. commerce and will help determine the chemicals EPA prioritizes for risk evaluation. Read more: https://www.epa.gov/tsca-inventory/tsca-inventory-notification-active-inactive-rule.
The Final Rule (TSCA Inventory Notification (Active/Inactive) Rule) was published on August 11, 2017. Supplier companies will have 180 days to report all chemicals manufactured or imported during the past 10-year period. (See further below for specifics applying to processing companies.) A number of chemical substances are excluded, such as naturally occurring substances, mixtures, exempt polymers, articles, R&D substances, etc. There is a section of the standard 40 CFR 710.26 outlining Chemical substances for which information is not required: https://www.epa.gov/tsca-inventory/list-active-substances-exempt-tsca-inventory-notifications-active-inactive-rule#download.
EPA has published the interim Active TSCA Inventory using reporting from the 2012 and 2016 Chemical Data Reporting cycles: https://www.epa.gov/tsca-inventory/how-access-tsca-inventory.
The regulated community is required to add all other active Chemical Abstract Service (CAS) registration numbers that were manufactured or imported during the 10-year retrospective period to the active list. Companies are responsible for identifying all chemical substances that are known or reasonably ascertainable.
Companies that are only chemical processors have an additional 240 days to review the interim Active TSCA Inventory and report any additional chemicals that may have been overlooked by their suppliers. The Notice of Activity Form A will be used for retrospective reporting and the Notice of Activity Form B will be used for forward-looking reporting. Forms will need to be submitted via the EPA’s Central Data Exchange (CDX).
Companies that fail to report are in violation of TSCA Section 15 and may be subject to penalties (40 CFR 711.1(c)).
If you would benefit from having someone examine this new Rule and how it may affect your reporting requirements for the substances you manufacture, import, or process, please contact the author, Scott K. Wilson, MS, CIH, CSP, CHMM, at email@example.com; 630-963-6026.
Ohio EPA’s new Multi-Sector General Permit (MSGP) for Industrial Stormwater Discharges (Ohio EPA (OEPA) General Permit Number OHR000006) was issued final on May 8, 2017. The effective date of the permit is June 1, 2017. OEPA’s fifth-generation MSGP (OHR000005) expired on December 31, 2016, and its replacement has incorporated changes that clarify allowances and exceptions and ensure that Ohio’s MSGP is consistent with its U.S. EPA counterpart. This post describes some important dates for associated submittals and summarizes new provisions of the permit.
Companies with facilities currently covered by OHR000005 should expect to receive a letter from OEPA in the next few weeks. No action is required of current permit holders until this letter is received.
Important dates to keep in mind:
- Effective permit date: June 1, 2017
- Permit expiration date: May 31, 2022
- Notice of Intent (NOI) submittal deadline date for existing permit holders: within 90 days of the OEPA’s written instructions (letter) to re-notify. Per Jason Fyffe, Supervisor, OEPA Central Office Stormwater Permitting, renewal letters will be mailed late the week of May 22, at the earliest.
- Stormwater Pollution Prevention Plan (SWPPP) update timeframe for existing permit holders: within 180 days of the effective date of the permit (i.e., November 28, 2017)
- Facilities not covered under a prior NPDES permit (new dischargers) must prepare a SWPPP prior to submitting an NOI. NOIs for new dischargers are to be submitted at least 180 days prior to discharge.
It is important to note that as of February 1, 2017, OEPA has instituted an all-electronic NOI filing policy, and facilities must use eBusiness to prepare and submit the form. If you prefer, the NPDES application utility (Surface Water Tracking, Reporting, and Electronic Application Management System or STREAMS) allows consultants to prepare the NOIs on behalf of their clients and delegate the forms to the appropriate individual for electronic signature and final submittal. CEC can assist you with this matter. Online payment is also available.
Notable changes to the current MSGP compared to OHR000005 include the following:
- Clarifying language was added that defines conditions when pavement wash waters and routine external building washdown are an allowable non-stormwater discharge authorized by the permit. MSGP Part 1.1.3.
- A list of the stormwater discharges subject to effluent limitation guidelines under 40 CFR, Subchapter N that are not eligible for coverage under the general permit and would require authorization to discharge under an individual NPDES permit is now included in MSGP Part 188.8.131.52.
- A reduction in required frequency for routine facility inspections and quarterly visual assessments is now allowed for facilities recognized under the Gold and Platinum levels by OEPA’s Encouraging Environmental Excellence (E3) Program. MSGP Parts 4.1.3 and 4.2.3.
- The requirement for a comprehensive annual site inspection has been eliminated in order to match the U.S. MSGP and to “eliminate redundancies and reduce burden” on facilities. The requirement for routine facility inspection remains, and required procedures are listed in MSGP Part 4.1.1 (no change from OHR000005).
- Language has been added to clarify that documents incorporated into the SWPPP by reference may be maintained on site electronically (i.e., satisfies “available on site” requirement). MSGP Part 184.108.40.206.
- Permittees are now required to make their SWPPP available to the public when requested, excluding any confidential or restricted business information. MSGP Part 5.3.
- Language has been added to clarify that, for monitoring purposes, an outfall can include a discrete conveyance (i.e., pipe, ditch, channel, tunnel, or conduit) or a location where sheet flow leaves the facility property. MSGP Part 6.1.1.
- Language has been added to clarify that permittees obtaining coverage in years 4 and 5 of the general permit must complete benchmark monitoring requirements to the extent of remaining monitoring periods available before the general permit expires. (Permittees obtaining coverage before this time are to complete the benchmark monitoring requirements within the first three years of permit coverage. This has not changed from OHR000005.) MSGP Part 220.127.116.11.
- Provisions have been added for permittees who are exceeding a benchmark due to neighboring facility run-on to account for this situation. MSGP Part 18.104.22.168.
- Provisions have been added for a facility to default to a different benchmark value if a parameter’s water quality standard is less restrictive than the permit benchmark value. MSGP Part 22.214.171.124.
- Provisions have been added for permittees to consider pollutant concentrations (contributions) from the facility structures (roofs, walls, fencing, etc.) when determining whether it is available, practical, and achievable to implement additional control measures when a benchmark has been exceeded. MSGP Part 126.96.36.199.
- The annual report requirements have been revised to be consistent with the federal MSGP. (The frequency and recordkeeping requirements have remained the same.) MSGP Part 7.2 and Appendix I.
- Language has been added to clarify that the discharge of leachate (defined in OAC 3745-27-01(L)(1)) is not authorized under the MSGP. MSGP Part 8.C.2.1.
- Composting fertilizer mixing facilities (SIC 2875) have been removed from Subsector C1 and located in a newly created Subsector C6, which provides more appropriate benchmark monitoring parameters for this industry. Table 8.C-1 and Appendix D to Sector C have been revised to specify that SIC 2875 (non-composting fertilizer mixing facilities) will be subject to Subsector C1 and SIC 2875 (composting fertilizer mixing facilities) will be subject to Subsector C6.
- Language was added to Sector N (Scrap Recycling Facilities) to clarify that references to secondary containment under this part are referencing stationary outdoor equipment and not mobile equipment. MSGP Part 8.N.3.1.7.
- Marinas have been added to Sector Q (Water Transportation) of the MSGP. The current OEPA Marina stormwater general permit (OHRM00002) expires on January 21, 2018, and will not be renewed. Marinas with coverage under OHRM00002 will remain covered under that general permit until it expires, and at that time, will be instructed to renew their coverage under OHR000006. NOTE: the current Marina Stormwater general permit authorizes the discharge of boat wash water if no detergents or other chemical cleaning agents are used. OHR000006 does not authorize boat wash water. Such discharges would require proper collection and disposal (i.e., sanitary sewer) or be permitted by a separate NPDES permit. MSGP Part 8, Subpart Q – Sector Q
- Appendix B, “Standard Permit Conditions,” has been updated to reflect the “Standard Permit Conditions” language found within OEPA general permits.
For additional information regarding OHR000006, including fact sheets and a copy of the permit, visit OEPA’s Industrial Stormwater General Permit website.
If you have any questions on how the requirements of OHR000006 may affect your facility, or if you would like assistance with NOI submittal and/or updating the SWPPP for your facility, contact Amy Ritts (firstname.lastname@example.org) or Andy McCorkle (email@example.com).
Update — EPA issues final New Source Performance Standards for Oil and Gas with significant new compliance requirements
On June 3, 2016, U.S. Environmental Protection Agency (EPA) finalized amendments to the Standards of Performance for Crude Oil and Natural Gas Production, Transmission and Distribution (Quad O) and a new subpart at 40 CFR 5360a et seq. (Quad Oa) for post-September 18, 2015, affected facilities. As noted in a previous CEC blog on this topic, U.S. EPA received nearly one million comments following the initial proposal. The new Quad Oa rule establishes emission standards for both methane and volatile organic compounds (VOC) at natural gas and oil well sites, production gathering and boosting stations, natural gas processing plants, and compressor stations. There are several new requirements for oil and natural gas production-related activities in these new federal rules, and it is important to understand how these rules might impact ongoing compliance activities under existing state rules and permit requirements already in effect. In this update, we focus on two of these new requirements due to their history and interrelatedness.
It is clear in reading both the proposed and final rules that U.S. EPA has expanded its understanding of oil and natural gas operations, particularly with respect to upstream E&P. Notably, the requirement for a professional engineer (PE) to evaluate and certify closed vent system design brings a new level of scrutiny borne out of a consent decree with a major oil and gas producer, and placed into practice in both the September 2015 Compliance Alert and the ongoing enforcement initiative targeting “energy extraction activities.” Not only is this new requirement intended to bring industry resources to bear on what the Agency views as a significant issue, but it also attaches professional liability to any subsequent violations attributed to closed vent system design. Further, with additional attention being focused on closed vent system design, the next obvious move on the Agency’s part was either construction practices (which are in many cases guided by industry consensus standards) or the operator’s preventative maintenance program.
From an air pollution control perspective, one focus of an upstream E&P maintenance program is to minimize or eliminate fugitive emissions from production facility equipment. As addressed by the industry during the comment period, there is an economic incentive to minimize losses of otherwise saleable products. Rather than dictate the contents of a preventative maintenance program, the Agency has instead required operators to survey for and repair fugitive emissions at well sites. While not a maintenance program per se, the new rule will require operators to engage in some routine maintenance and communication planning to ensure that fugitive leaks discovered during a survey are repaired and verified within the allotted timeframe.
Many producers operating in the Utica and Marcellus plays already had some form of fugitive emissions survey requirements in effect, as does Colorado. In other states, this will be the first time operators will have to grapple with leak detection and repair programs. This new requirement will have a disparate impact on upstream E&P operators that do not have the resources to employ full-time environmental staff or purchase the equipment needed to perform these required fugitive leak surveys in-house.
A summary of the new requirements discussed above is provided here. In the meantime, if you have questions on any aspects of the NSPS for the oil and natural gas source category, please contact the post authors: Kris Macoskey (firstname.lastname@example.org), or Ben Blasingame (email@example.com).
For those interested in exploring this topic further:
Final NSPS OOOO and OOOOa rule from the Federal Register
U.S. EPA National Enforcement Initiatives
CEC’s previous blog: EPA Receives Nearly One Million Comments on Proposed New Source Performance Standards for Oil and Gas
On June 3, 2016, U.S. Environmental Protection Agency (EPA) published a proposed Information Collection Request (ICR) for the oil and natural gas industry in the Federal Register for notice and comment. Once the comment period ends and EPA provides responses to all significant comments, the amended proposal will be sent to the Office of Management and Budget (OMB) for review and approval. If approved, and U.S. EPA is issued a valid OMB control number, U.S. EPA would begin collecting information from oil and natural gas companies. The Agency envisions the collection process to begin in October 2016.
The purpose of the ICR is to collect detailed information to support regulation of existing oil and natural gas stationary sources. This is in contrast with recent regulatory efforts, which have focused (primarily) on new or modified sources. The information from the proposed ICR will be used to develop a pathway for the phase-in of new standards, rather than making those standards become effective for all affected sources at once.
Based on the proposal, the ICR will be divided into two parts. The first part will be sent to all oil and natural gas operators and requires information with respect to the company and its operations. The second part requires more detailed information with respect to specific sources and could involve a significant time investment from environmental and operations teams to complete. In addition, the second part of the ICR may require information that many organizations would consider confidential. Companies with confidentiality concerns may want to involve their legal teams in this process.
Also, keep in mind that this ICR will be issued under U.S. EPA’s authority under Section 114 of the Clean Air Act. This means that the Agency has the legal authority to require all responses to the ICR be certified by a responsible official and establish a deadline for providing a response.
For those interested in reading more about the proposed ICR, the U.S. EPA has a dedicated website here. Civil & Environmental Consultants, Inc. will be following the ICR approval process closely, and plans on updating this post as events unfold. In the meantime, if you have any questions with respect to the ICR or other recent federal air pollution regulatory activity, please contact Ababu Gelaye at 888-598-6808 or firstname.lastname@example.org.
The next submission period for the U.S. EPA’s Chemical Data Reporting (CDR) requirement under the Toxic Substances Control Act (TSCA) is from June 1, 2016, through September 30, 2016, and will cover the 2012 – 2015 reporting years. The previous CDR submission was in 2012 for the 2010 and 2011 reporting years.
Manufacturers and importers of TSCA inventory-listed chemical substances that exceed either the reduced reporting threshold (2,500 lbs/yr for certain chemical-specific TSCA Actions) or the standard reporting threshold (25,000 lbs/yr for all other listed chemicals) for any calendar year from 2012 through 2015 must prepare a CDR for each chemical exceeding the respective thresholds and submit to U.S. EPA. Note that a CDR must be submitted covering all four reporting years if a facility exceeds an applicable threshold in any year.
For chemicals that are imported to the U.S., note that only the primary importer of a chemical (generally the entity responsible for payment of import tariffs) has the TSCA CDR responsibilities. A facility that purchases an imported chemical from the primary importer (or other down-stream entity) is not responsible for preparation of a TSCA CDR for that chemical.
The report must be filed electronically using the U.S. EPA’s Central Data Exchange (CDX) and must include production quantities for calendar years 2012, 2013, 2014 and 2015, as well as the following information for 2015:
- Manufacturing Related Data
- Chemical ID,
- Production quantity,
- Number of workers on site who are likely to be exposed to the chemical,
- Maximum concentration, and
- Physical forms and relative production of each form.
- Processing Related Data
- Types of processes / use (up to 10),
- Industrial function categories,
- Percent of production,
- Number of sites, and
- Number of workers off site who are likely to be exposed to the chemical.
- Consumer and Commercial Use Related Data
- Product categories,
- Whether the product is intended for use by children,
- Percent of production,
- Concentration range, and
- Number of commercial workers who are likely to be exposed to the chemical.
For the 2016 submission, calendar year 2015 is the principal reporting year, which requires the presentation of enhanced manufacturing / processing and use data.
Whether a chemical substance is covered or not covered by TSCA can be determined by searching the U.S. EPA’s Substance Registry Services (SRS) web page.
Note that the current TSCA list includes more than 60,000 chemicals.
Chemicals applicable to CDR submission are identified as “TSCA Inv” in the chemical-specific search tables.
Common chemical substances (by industry sector) included on the TSCA inventory that may be subject to CDR requirements include:
- Primary Metals – Steel, Slag, Baghouse Dust, Copper, Zinc, Manganese and Chromium;
- Secondary Metals – Mill Scale, Zinc Oxide and Ferro Manganese;
- Aggregates – Lime, Hydrated Lime, Bentonite and Kaolin;
- Power – Coal Ash;
- Paper – Secondary Treatment Sludge;
- Refineries – Gasoline and Diesel Fuel;
- Industrial Gases – Hydrogen, Oxygen, and Nitrogen; and
- Miscellaneous – Glass, Tanning Waste and Cement.
TSCA includes a number of important exemptions from CDR reporting, including:
- Byproducts that are disposed (i.e., not released to commerce) need not be reported;
- A chemical present as an impurity (unintentionally present in another chemical substance) is exempt from reporting;
- Polymers have a full reporting exemption;
- Naturally occurring chemical substances have a full reporting exemption; and
- Certain listed forms of natural gas and natural gas liquids have a full reporting exemption.
In addition, partial exemptions are available for certain petroleum process streams and for other common chemical substances (e.g., limestone, hydrogen, oxygen, nitrogen).
Additional information on the TSCA CDR program is provided on the U.S. EPA’s Chemical Data Reporting web page.
If you have any questions about the 2016 TSCA Chemical Data Reporting, please contact Dennis Ritter at email@example.com or 412-429-2324.
The first Federal limits on various metals and other pollutants discharged by steam electric power plants were finalized on September 30, 2015, and published in the Federal Register on November 3, 2015. Limits for arsenic, lead, mercury, selenium, chromium, and cadmium are established in the new rules. EPA notes that steam electric power plant sources make up approximately 30 percent of the toxic and bio-accumulative pollutants discharged into surface waters of the United States by all industrial categories under the Clean Water Act. The Final ELGs set Daily Maximum and 30-Day Average Effluent Limits for discharges from existing and new sources for Flue Gas Desulfurization (FGD) (see 1. below), Gasification (see 2. below), Combustion Residual Leachate (see 3. below), and Chemical Metal Cleaning Wastewaters (see 4. below). Also established are zero discharge requirements for Flue Gas Mercury Control (FGMC), Fly Ash Transport, and Bottom Ash Transport Waters.
The electric power industry has made great strides to reduce air pollutant emissions under Clean Air Act programs, yet many of these pollutants may be transferred to the wastewater as plants employ technologies to reduce air pollution. When metals such as mercury, arsenic, lead, and selenium accumulate in fish or contaminate drinking water, they can potentially cause adverse effects in people who consume the fish or water.
This final rule is the first to ensure that generating stations in the steam electric industry employ technologies designed to reduce discharges of trace metals and other potentially harmful pollutants discharged in the plants’ wastewater. Sources of drinking-water have been identified with increased levels of carcinogenic disinfection by-products (brominated DBPs, in particular trihalomethanes (THMs)) from bromide in the plants’ wastewater. This was tracked from drinking-water utilities’ violations of the THM Maximum Contaminant Level (MCL). Nitrogen discharged by steam electric power plants can also impact drinking-water sources by contributing to algal blooms in reservoirs and lakes that are used as drinking-water sources. Mercury and selenium can bioaccumulate in fish and wildlife, and also accumulate in the sediments of lakes and reservoirs.
The Steam Electric Power Generating Effluent Guidelines and Standards that EPA promulgated and revised in 1974, 1977, and 1982 did not reflect process and technology advances that have occurred in the last 30-plus years (e.g., coal gasification) and the widespread implementation of air pollution controls (e.g., FGD and FGMC). The technological advances have altered waste streams and created new types of wastewater at many steam electric power plants, particularly coal-fired generating stations. Many stations, none-the-less, still treat their wastewater using only surface impoundments, which may be ineffective at controlling discharges of toxic pollutants and nutrients.
1. FGD Wastewater
FGD systems are used to remove sulfur dioxide from the flue gas so that it is not emitted into the air. Dry FGD systems spray sorbent slurry into a reactor vessel so that the droplets dry as they contact the hot flue gas. Although dry FGD scrubbers use water in their operation, the water in most systems evaporates, and the dry FGD scrubbers generally do not discharge wastewater. Wet FGD systems contact the sorbent slurry with flue gas in a reactor vessel, producing a wastewater stream.
Best Available Technology (BAT) required for control of pollutants discharged in FGD wastewater is a chemical precipitation system that employs hydroxide precipitation, sulfide precipitation (organo-sulfide), and iron co-precipitation, followed by an anoxic/anaerobic fixed-film biological treatment system designed to remove heavy metals, selenium, and nitrates. At some stations, this wastewater is managed in surface impoundments, constructed wetlands, or through practices achieving zero discharge. Other technologies have been evaluated or are being developed to treat FGD wastewater, including iron cementation, zero-valent iron (ZVI) cementation, reverse osmosis, absorption or adsorption media, ion exchange, and electrocoagulation.
2. Gasification Wastewater
Integrated Gasification Combined Cycle (IGCC) plants use a carbon-based feedstock (e.g., coal or petroleum coke) and subject it to high temperature and pressure to produce a synthetic gas (syngas), which is used as the fuel for a combined cycle generating unit. After the syngas is produced, it undergoes cleaning prior to combustion. The wastewater generated by these cleaning processes, along with any condensate generated in flash tanks, slag handling water, or wastewater generated from the production of sulfuric acid, is referred to as “grey water” or “sour water,” and is generally treated prior to reuse or discharge.
3. Combustion Residual Leachate from Landfills and Surface Impoundments
Combustion residuals generally collected by or generated from air pollution control technologies comprise a variety of wastes from the combustion process. These combustion residuals can be managed at the station in on-site landfills or surface impoundments. Leachate includes liquid, including suspended or dissolved constituents, that has percolated through or drained from waste or other materials placed in a landfill, or that passes through the containment structure (e.g., bottom, dikes, berms) of a surface impoundment. Most landfills have a system to collect the leachate. In a lined landfill, the combustion residual leachate collected by the liner is typically transported to an impoundment (e.g., collection pond). Some generating stations discharge the effluent from these impoundments containing combustion residual leachate directly to receiving waters, while other stations first send the impoundment effluent to another impoundment handling the ash transport water or other treatment system (e.g., constructed wetlands) prior to discharge.
Surface impoundments are the most widely used systems to treat combustion residual leachate. Some generating stations collect the combustion residual leachate from impoundments and recycle it back to the impoundment from which it was collected. Some generating stations use collected leachate as water for moisture conditioning of dry fly ash prior to disposal, or for dust control around dry unloading areas and landfills.
4. Chemical Metal Cleaning Wastewaters
Chemical metal cleaning wastewaters are generated from cleaning metal process equipment and are most typically treated in surface impoundments and chemical precipitation systems. Other types of treatment and disposal include constructed wetlands, filtration, reverse osmosis, clarification, oil/water separation, brine concentration, recycling, evaporation, off-site treatment, hazardous waste disposal, third party disposal, landfilling after mixing with fly ash, and deep well injection.
Many power generating stations that are currently using impoundments or basic treatment may find that additional measures are required to achieve the new ELG limits. Table 1 provides a summary of effluent limits for discharges from existing sources, while Table 2 provides a summary of effluent limits for discharges from new sources. Table 3 provides a summary of additional effluent limits that will apply for discharges from new sources that produce greater than 25 megawatts (MW). Power generating stations will likely have issues associated with the treatment of selenium and boron in their FGD blowdown. These compounds can be difficult to treat and are not always readily removed using conventional treatment techniques that are currently employed by power generators. As such, additional treatment processes may be required to satisfactorily remove these compounds. CEC has experience in the treatment and removal of these compounds and can assist with evaluation of power station water balances, wastewater sampling and testing, and wastewater treatment plant design.
If you have any questions about the November 2015 Steam Electric Power ELGs and their potential impacts on your station, please contact Ron Ruocco, P.E., at firstname.lastname@example.org or 855-859-9932.
Table 1: Summary of Effluent Limits for Discharges from Existing Sources
(Daily Maximum/30-Day Average)
|Steam Electric Plant Process||Arsenic
as N (mg/L)
|FGD Wastewater||11 / 8||788 / 356||23 / 12||17.0 / 4.4||100 / 30||–||20 / 15|
|Gasification Wastewater||4 / –||1.8 / 1.3||453 / 227||–||100 / 30||38 / 22||20 / 15|
|Combustion Residual Leachate||–||–||–||–||100 / 30||–||20 / 15|
Existing Sources: The final rule establishes Best Available Technology (BAT)-based effluent limits in existing FGD wastewater, existing gasification wastewater, and existing combustion residual leachate discharges. These limits are equivalent to Best Practicable Technology (BPT).
Table 2: Summary of Effluent Limits for Discharges from New Sources
(Daily Maximum/30-Day Average)
|Steam Electric Plant Process||Arsenic
|FGD Wastewater||4 / –||39 / 24||5 / –||–||–||100 / 30||50 / 24||20 / 15|
|Gasification Wastewater||4 / –||1.8 / 1.3||453 / 227||–||–||100 / 30||38 / 22||20 / 15|
|Combustion Residual Leachate||11 / 8||788 / 356||–||–||–||100 / 30||–||20 / 15|
|Low Volume Waste Sources||–||–||–||–||–||100 / 30||–||20 / 15|
|Chemical Metal Cleaning Wastes||–||–||–||1 / 1||1 / 1||100 / 30||–||20 / 15|
New Sources: For new FGD wastewater, new gasification wastewater, new combustion residual leachate discharges, new low-volume waste sources, and new chemical metal cleaning waste sources, the final rule imposes effluent limitations based on New Source Performance Standards (NSPS).
Table 3: Summary of Additional Effluent Limits for Discharges from New Sources
(Generating Stations Producing Greater Than 25 MW)
(Daily Maximum/30-Day Average)
|Pollutant or Pollutant Property||Once Through Cooling||Cooling Tower Blowdown||Coal Pile Runoff|
|Free available chlorine||mg/L||0.20 / 0.20||0.50 / 0.20||–|
|Total Suspended Solids||mg/L||–||–||50 / 50|
|The 126 priority pollutants (Appendix A) contained in chemicals maintenance, except:||mg/L||–||(1)||–|
|– Chromium, total||mg/L||–||0.2 / 0.2||–|
|– Zinc, total||mg/L||–||1.0 / 1.0||–|
(1) Denotes No Detectable Amount