Unexpectedly replacing a tank can strain your budget and always seems to come at the most inopportune times. Based on my experience with tank inspections, one of the most common reasons for unexpected tank replacements is using an Underground Storage Tank (UST) as an Aboveground Storage Tank (AST).
Any STI/SPFA SP001 Certified Inspector can identify a misused UST during the required periodic inspections of ASTs, and these tanks are also commonly discovered during site visits related to drafting or updating Spill Prevention, Control, and Countermeasure (SPCC) Plans. Budget and complete a tank replacement before your next inspection. During my inspections, I use three indicators when looking at a tank to identify if a UST is misused as an AST:
No Emergency Vent! The most important reason not to use a UST aboveground.
If the unthinkable happens and you have a fire around your tank without proper emergency venting, that tank fire can go from bad to BOOM!
The design of ASTs is to minimize the danger of being engulfed in flames to release the vapors from the tank in a controlled manner. In contrast, a UST design will never be engulfed in flames, so the tank manufacturer does not install an emergency vent port.
Properly sizing an AST emergency vent to release the increased vapor pressure during a fire is important, too. The need to release the higher pressure makes emergency vents much larger than the normal vents for simple atmospheric changes. The larger emergency vents come in five varieties:
Flip-up vents are spring-loaded caps held closed by a latch designed to release at a set pressure or temperature. If the latch doesn’t work and the flip-up cap is open, duct tape or a well-placed brick is not the proper solution; you’ll need to replace the latch. Luckily, the latches are readily available, and the latch installation is usually simple.
Rupture disks are vent covers where the entire cover breaks open when a set pressure or temperature is exceeded, instead of just the latch like in the flip-up vents.
Pop-up vents are weighted caps that sit on the vent until the pressure in the tank reaches the designed level. During fire incidents, these vents periodically release the built-up vapors, preventing the tank from rupturing. If this vent is not staying seated correctly, repair or replace the vent.
Long bolt manholes function similarly to the pop-up vents to periodically release built-up vapors. This type of vent relies on the bolts securing the manhole cover to have the designed amount of slack between the manhole rim and the nuts. I’ve seen too many long bolt manholes with the nuts fully tightened to the rim, completely negating the vent’s purpose and safety. A simple fix for this issue is to replace the fully threaded bolts with properly sized partially threaded bolts.
New tanks are unlikely to have Weak Roof-to-Shell joints. Occasionally, I’ve seen them in older single-wall vertical tanks, where the roof construction has a particular area break when the tank pressure gets too high.
Unreviewed Damage: Most USTs as ASTs are old and damaged
Frequently pulling these tanks results in dents or scraps to the UST. Remove any damaged tanks from service until a qualified inspector or engineer can review the damage. Additionally, most states prohibit the reuse of USTs once they are removed from their original installation location.
It may be difficult to see in this image, but the tank is scratched, dented, and starting to rust.
No Tank Saddles
Most of the repurposed USTs are horizontal, so these tanks require chocks or an earthen berm to keep them in place. Saddles act as the welded attachment areas for the tank legs and distribute the weight over the tank’s belly — part of the AST design. Sometimes, people with good intentions get too creative and attempt to turn a UST into a vertical AST. However, the presence of vent connections along the side of the tank and none on the tank top is a sure sign the tank is not in use appropriately.
Best practice — look for these warning signs before inspections and drafting or updating SPCC Plans.
About the Author: Benjamin Reynolds is a Senior Project Professional in our Little Rock, Arkansas, office. His recent experience includes serving as a Technical Branch Manager for the Arkansas Department of Environmental Quality where he led a team of engineers, toxicologists, and site assessors to review and guide site assessments and remediation projects throughout the state. He is experienced in Phase I and Phase II Environmental Site Assessments, as well as Spill Prevention, Control, and Countermeasures (SPCC) Plans, and Storm Water Pollution Prevention Plans (SWPPPs). He is a Professional Engineer licensed in Arkansas, Oklahoma, and Tennessee. Reach out to Ben at or on LinkedIn.
The U.S. Environmental Protection Agency (EPA) announces the availability of up to $4.6 billion of competitive grants. The grants are broken into two funding opportunities. The Climate Pollution Reduction Grants (CPRG) competition is designed to incentivize eligible applicants to apply for funding together as a coalition to implement GHG reduction measures regionally, across multiple municipalities, state boundaries, or even state and tribal boundaries. It includes funding for enhancing carbon removal, too.
Deadlines to Apply for Grants to Implement GHG Reduction
Under Funding Opportunity Number EPA-R-OAR-CPRGT-23-07, EPA announces approximately $4.3 billion for a general competition open to states, municipalities, air pollution control agencies, tribes, and territories for CPRG implementation grants. Tribes and territories interested in the general competition should seek the CPRG implementation grant “general competition” NOFO for more information. Applications for this implementation grants competition for tribes and territories are due on May 1, 2024.
Another $300 million for the CPRG implementation grants competition is exclusively for tribes and territories. Lead organizations for tribes and territories must submit their Priority Climate Action Plans to EPA by the deadline of April 1, 2024, in order for lead organizations and other eligible applicants under this announcement to submit grant applications to fund measures contained in those plans. EPA anticipates awarding approximately 25 to 100 grants ranging between $1 million and $25 million under this tribes and territories competition. Further detail on award tiers can be found in Table 1 of Section II.B.
Climate Change Disruptions
As the US faces the increasingly harmful impacts of climate change, communities are experiencing more deadly wildfires and storm surges, more extreme drought and water scarcity, and dangerous levels of flooding, among other impacts. The Fourth National Climate Assessment found that intense extreme weather, climate-related events, and changes in average climate conditions are expected to continue damaging infrastructure, ecosystems, and social systems that provide essential benefits to communities. If left unchecked, future climate change is expected to disrupt many areas of life further and exacerbate existing challenges to prosperity posed by aging and deteriorating infrastructure, stressed ecosystems, and long-standing inequalities.
Grants to Support Your Communities
Our country’s daunting challenge comes with an opportunity to invest in a cleaner economy that will spur innovation and economic growth while building more equitable, resilient communities. Accordingly, the Climate Pollution Reduction Grants program is designed to achieve the following goals:
1. Implement ambitious measures that will achieve significant cumulative GHG reductions by 2030 and beyond;
2. Pursue measures that will achieve substantial community benefits (such as reduction of criteria air pollutants (CAPs) and hazardous air pollutants (HAPs));
3. Complement other funding sources to maximize these GHG reductions and community benefits; and,
4. Pursue innovative policies and programs that are replicable and can be “scaled up” across multiple jurisdictions.
What Qualifies as a GHG Reduction Measure?
Treatments and solutions that reduce GHG emissions or enhance carbon removal can qualify. Measures that enhance carbon removal increase carbon dioxide removal from the atmosphere through, for example, the uptake of carbon and storage. Other measures may include EPA-approved technologies. Documentation must be provided to support the estimated GHG emission reductions for each proposed measure. Depending upon the proposed solution, you’ll need a well-conceived plan and data from a reliable environmental engineer or an environmental or sustainability consultant.
Who’s Eligible?
Eligible applicants for the CPRG implementation grants competitions are lead organizations for CPRG planning grants and other executive branch-level agencies, offices, and departments in states, D.C., Puerto Rico, municipalities, tribes, tribal consortia, territories, and groups of such entities applying for funding to implement measures contained in one or more applicable Priority Climate Action Plan developed with funding from a CPRG planning grant.
Additional Resources
Webinars:
EPA will host overview webinars for each implementation grant competition for eligible applicants and other interested parties over the coming weeks. All sessions will be one hour long. EPA will post recordings of each webinar to the CPRG website. You can click the links below to register for one or more scheduled sessions.
Date | Time (ET) | Event Topic | Register |
Sept. 21 | 2:30 pm | General competition webinar | Register here |
Sept. 27 | 2:00 pm | Tribe and territories only competition webinar | Register here |
Oct. 3 | 3:00 pm | General competition webinar (repeat) | Register here |
Oct. 5 | 1:00 pm | Tribe and territories only competition webinar (repeat) | Register here |
The other night, I woke up in a bit of a panic and thought that I must have missed an announcement by the USEPA regarding the PM2.5 NAAQS reconsideration! Did I?
The answer, thankfully, is no! However, that is not any reason to relax and take no action.
By way of background, the Clean Air Act requires that the USEPA set National Ambient Air Quality Standards (NAAQS) for each of the criteria air pollutants, including particulate matter (PM). These NAAQS are based on the best available science and aim to protect human health and welfare. In June of 2021, the USEPA announced that they would reconsider the 2020 PM NAAQS final action under the prior administration that did not lower any standards. Then, in January 2023, the USEPA published the proposed rule to revise the PM2.5 primary annual standard down from 12 micrograms per cubic meter (µg/m3) to within a range of 9-10 µg/m3. In that proposal, the agency retained the 24-hour standard of 35 µg/m3.
The comment period for this proposed rule has since closed, and the agency is now working through over 5,000 submitted comments. It is unclear when the USEPA will issue the final rule (it could be any day now) and if the new annual standard will be set at 9 or 10 or something in between.
What does this mean for me as a regulated source? What should you do? SCS Engineers recommends the following actions:
Additional Resources:
About the Author: Rafe Christopherson, PE, is a project director and SCS’s industrial Clean Air Act leader. He is an air quality professional with a wide variety of experience over his 25-year career. His expertise includes consulting, working at an air quality regulatory agency and with industry. His expertise includes semiconductors, biofuels, pulp and paper, hardwoods, power generation, refineries, and general manufacturing. If you are interested in more information on this PM2.5 NAAQS reconsideration process and what it might mean for your business, you may reach Rafe at or via LinkedIn.
On August 17, 2023, the United States Environmental Protection Agency (EPA) released the first of twelve datasets (representing approximately 7% of the total data that it plans to collect) on 29 polyfluoroalkyl substances (PFAS) and lithium (an alkali metal) in our nation’s drinking water. This sampling will continue through 2026, and is the latest action delivering on the EPA PFAS Strategic Roadmap, which dictates that PFAS (an emerging contaminant pending regulations under CERCLA) requires a multi-agency approach and specific actionable steps to assess risks to human and environmental health better, hold polluters accountable, and identify the extent of the problem.
Monitoring PFAS and lithium is currently under the fifth Unregulated Contaminant Monitoring Rule (UCMR 5). The Safe Drinking Water Act (SDWA) requires that the EPA issue a list of unregulated but potentially harmful contaminants every five years and devise a protocol for monitoring those contaminants in public water systems (PWSs).
The current UCMR 5 regulatory framework allows for collecting PFAS and lithium data throughout the United States. It aims to create science-based decision-making regarding how to address these chemicals best. Results, which will get quarterly updates, can be reviewed by the public on the EPA’s National Contaminant Occurrence Database.
While there is not currently a final drinking water standard in place for PFAS, EPA has already issued health advisories for four PFAS compounds, and two of them – perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) – have also been proposed for entry as hazardous substances under CERCLA, as of March 2023. The timeline for the final rule on PFAS CERCLA designation is now February 2024. Landfills and other passive receivers are seeking relief from CERCLA contribution litigation prior to designating PFAS as hazardous substances, as they have no control over the use and disposal of hundreds of thousands of products containing PFOA and PFOS.
This first set of data does appear to raise some red flags, though it is not uniformly indicative of widespread contamination. In Missouri, for example, 1,923 distinct water samples were obtained from 22 different PWSs (from a mix of wells and treatment plants) in communities throughout the state. Of these samples, 23 are scattered between 11 facilities containing lithium at concentrations in excess of the laboratory Method Reporting Limit (MRL) of 9 micrograms per liter (µg/L), some by many orders of magnitude. Only two PFAS compounds (PFOS and PFHxS) are above their MRLs (0.004 µg/L and 0.003 µg/L, respectively), both from the North Rodeo Well of the Camdenton PWS.
This data will ultimately be immensely useful for public sector officials trying to make policy decisions regarding PFAS and lithium management, fine-tuning community engagement/education efforts, and for private sector industries seeking to get a handle on potential liabilities. SCS Engineers and other qualified environmental firms are poised to be essential partners to national leaders in identifying and remedying emerging contaminants such as PFAS. Many technologies proven to work on a large scale are available, with more promising technologies on the horizon.
Find additional regulatory information using the links below:
Impacts on Sectors and Treatments:
About the Author: Rachel McShane, LEP, has over 15 years of experience in environmental due diligence projects (Phase I, II and III Environmental Site Assessments) as well as Brownfields redevelopment, risk-based corrective action, and remediation projects. She is familiar with National Environmental Policy Act (NEPA) environmental assessments, vapor investigations and mitigation, radon, asbestos, lead-based paint surveys, and leachate monitoring/solid waste management. Reach Ms. McShane at or via LinkedIn.
The proposed AERR rule would require nearly 130,000 facilities to report air toxics emissions directly to EPA. It would also give states the option to collect the air toxics data from industry (rather than states) and report it to EPA, provided the Agency approves their program. This proposed action would allow for EPA to annually collect (starting in 2027) hazardous air pollutant (HAP) emissions data for point sources in addition to continuing the criteria air pollutant and precursor (CAP) collection in place under the existing AERR.
Here are some key things to know about the proposed rule from the EPA website:
1. It would require air toxics (hazardous air pollutant) emissions reporting. While most states voluntarily report air toxics emissions data to EPA now, reporting is not consistent nationwide. The proposal would require many industrial facilities to report air toxics emissions data and offers states the option to report emissions on behalf of the industry sources in their states.
2. It would mean that more facilities must report emissions every year by using the same emissions thresholds every year to determine whether a facility’s detailed emissions information must be reported.
3. It would fill reporting gaps for some portions of Indian country and federal waters. The AERR proposal would require industry to report emissions for certain facilities that operate in those areas and that currently are not reported.
4. It includes provisions to limit the burden on small businesses. The proposal includes flexibilities such as allowing certain small businesses to report a facility’s total air toxics emissions instead of detailed data and exempting many collision repair shops from air toxics reporting requirements.
5. It would provide EPA information that would help the Agency improve its estimates of emissions from prescribed fires. EPA is committed to helping communities and our federal, state, local, and tribal partners manage the health impacts of smoke from wildland fires, including prescribed fires. Prescribed fire is a land management tool that can reduce the likelihood of catastrophic wildfires by reducing the buildup of unwanted fuels.
Additional Resources:
On July 1, 2023, the Illinois Environmental Protection Agency (IEPA) posted and updated General NPDES Permit No. ILR00 for Industrial Storm Water Discharges (2023 General Permit). The 2023 General Permit is effective July 1, 2023, through June 30, 2028.
Multiple industry sectors must now update their site-specific Storm Water Pollution Prevention Plan (SWPPP) to comply with the 2023 General Permit. Three key updates in the 2023 General Permit are:
1-Permittees are required to submit a Notice of Intent (NOI) for renewal no later than 150 days after the 2023 General Permit is issued (i.e., by November 28, 2023).
2-Permittees must place a sign of permit coverage (except in instances where other laws or local ordinances prohibit such signage) in a safe, publicly accessible location in close proximity to the facility and include the following:
3-Benchmark sampling requirement updates, varying based on the industry sector’s Standard Industrial Classification (SIC) Code classification:
List 1 – SIC Code Groups with Updated Benchmark Sampling Constituents
Subsector C1 & C2
Subsector E1 & E2
Subsector F1 & F2
Subsector H1
Subsector L1
Subsector M1
Subsector Q1
Subsector AA1
List 2 – SIC Code Groups with New Benchmark Sampling Requirements for Reporting Purposes Only
Subsector B2
Subsector C5
Subsector D2
Subsector E3
Subsector F5
Subsector I
Subsector J3
Subsector L2
Subsector N2
Subsector O1
Subsector P1
Subsector R1
Subsector T1
Subsector U3
Subsector V1
Subsector W1
Subsector X1
Subsector Y2
Subsector Z1
Subsector AB1
Subsector AC1
Our authors are available to answer questions about the Illinois stormwater regulations. You will find state professionals for updates or filing requirements local to your operation here.
Spencer LaBelle serves as a Senior Project Engineer for our Upper Midwest Team. Spencer has prepared SWPPPs for multiple, diverse industries and operations throughout Illinois and assisted clients with SWPPP inspections from the Illinois EPA. He has diverse experience in civil/environmental consulting for stormwater and erosion control management systems, site development, and regulatory compliance.
Betsy Powers serves as a Vice President/Senior Project Manager for our Upper Midwest Team. She has over 25 years of experience in civil/environmental consulting, including erosion control and stormwater management, site development, regulatory compliance, landfill design and permitting, landfill construction, material recovery facility design, and compost facility design and permitting.
Additional NPDES and Stormwater Resources:
In degraded ecosystems, manipulating sediments can aid in recreating natural sediment processes, establishing suitable substrate conditions for aquatic life, and supporting the recovery of vegetation and wildlife. In the United States, sediment management revolves around the presence of contaminated sediment. Contaminated sediment sites pose intricate technical challenges that demand significant resources to address and mitigate the associated problems effectively.
Over the past three decades, significant progress has reduced the discharge of toxic and persistent chemicals into waterways throughout the United States. However, a persistent problem remains, characterized by elevated concentrations of contaminants in the sediment found at the bottom of rivers and harbors. The situation has raised considerable concerns about its potential risks to aquatic organisms, wildlife, and humans.
This paper delves into the technical challenges environmental engineers and consultants face in addressing and mitigating this issue, especially during waterfront remediation projects. Furthermore, he explores strategies to optimize resources to tackle the problem at hand effectively and efficiently.
Active monitoring and data collection is critical throughout the remediation process. These activities enable evaluating the chosen strategy’s effectiveness, identifying necessary adjustments, and ensuring compliance with environmental regulations. Adaptive management approaches allow modifying or refining the sediment remediation strategy based on monitoring results and stakeholder feedback.
The utmost importance lies in choosing the appropriate remediation techniques; base the decision on site conditions, the specific contaminants present, and the desired remediation goals. After reading the paper, you may get a better idea of the options available for achieving effective and sustainable sediment remediation outcomes.
Early one Saturday morning, SCSers Chuck Houser, Luke Montague, Allison O’Neal, and me, Jen Morton, headed out to Brawley in the Imperial Valley region of Southern California. That is the desert. We had been having our usual May Gray here in SoCal when the summer can feel like winter at the coast, but the desert was a balmy 100 degrees and sunny that day.
We met with Sean Wilcock of the Imperial Valley Economic Development Corporation, one of our clients for Brownfields work, at a coffee shop in Brawley. From there, we ventured north to an area between Calipatria and Niland to see the beginning workings of a lithium extraction operation.
This region lies at the southern end of the San Andreas fault, where the motion between the North American and Pacific Plates begins to switch from strike-slip to extensional or from side-by-side to pulling apart. Where extension occurs, the crust tends to be relatively thin. Imagine pulling apart a sticky bun or taffy – the middle starts to get thinner before it breaks.
With the thinning of the crust, hot magma from the earth’s interior is closer to the surface. The heat from the magma heats the groundwater, which is A LOT beneath the Imperial Valley. And in this groundwater are minerals that, until recently, have not necessarily been worth the effort to extract from the water.
For decades energy companies have been using this super-heated water to generate electricity in the Imperial Valley. The hot water is pumped up from deep within the earth, using the steam to rotate turbines. The water is then pumped back into the aquifer.
Before our trip, Chuck and I met Tracy Sizemore, director of Battery Operations for Controlled Thermal Resources (CTR), at a San Diego Association of Geologists (SDAG) meeting learning more about the mineral resources in Imperial Valley. Chuck and I were as fascinated with that as the opportunity to see the biggest drill rig we’ve ever seen, which would be drilling an 8,000-foot well for groundwater extraction. We learned about the brine’s lithium resources (another term for the super-heated, mineral-rich groundwater).
Lithium has become a highly sought-after metal with the proliferation of electric vehicles. Given this increase in value, it is now economically feasible to extract it from the brine as part of the energy generation process. Some companies have plans to conduct the extraction in addition to electricity generation at existing geothermal plants. One company will build a separate extraction facility next to an existing plant.
CTR is planning to develop a plant that will focus primarily on the extraction of lithium, with energy generation being secondary. As Geologists, we got a tour of CTR’s prototype plant. It was fascinating to see all of the equipment and the results of the extraction process – a small bottle of lithium-rich liquid worth about $10. The extraction process also creates a sludge containing other important elements, including manganese, zinc, and even gold and silver. The plan is to sell the sludge to another company to extract the additional economic elements.
The process of extracting lithium in this manner is sustainable and much cleaner than traditional mining methods. It is also considered carbon-neutral. The new plant will generate enough electricity to power it 100%, with enough left over to power a battery manufacturing facility next door after its construction.
CTR’s lithium extraction process expects to bring 1,400 jobs to the area, with another 4,000 jobs once the battery plant is up and running. With the influx of workers, the Imperial Valley needs more infrastructure, housing, and services, so it is supporting economic growth.
In the fall, we plan to return to CTR’s facility to see the enormous rig drilling the 8,000-foot well!
Meet the Author – Jen Morton, Professional Geologist and SCS Project Manager
Consider a position with the finest pure-environmental firm in North America!
The Environmental Protection Agency (EPA) is proposing to designate perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), including their salts and structural isomers, as hazardous substances. The proposed rule published in the Federal Register designates two per- and polyfluoroalkyl substances (collectively, PFAS) constituents as CERCLA Hazardous Substances. While this is a small subset of PFAS constituents, PFOA and PFOS are reportedly the most commonly used and likely to be detectable. Additional PFAS compounds are certainly on the horizon for consideration by EPA and, in fact, an Advance Notice of Proposed Rulemaking was issued by EPA in April of 2023 to seek input for seven additional compounds for hazardous substance designation.
What Could This Mean For Property Transactions and Real Estate Development?
When the CERCLA hazardous substance rule becomes final (anticipated in 2023 or 2024), it will be mandatory to consider these PFAS constituents when performing Phase I Environmental Site Assessments (ESAs) to identify Recognized Environmental Conditions (RECs) in connection with a property. Because of the ubiquitous use of PFAS, often called “forever chemicals,” in residential, commercial, and industrial products, some Environmental Professionals are concerned that PFAS-related RECs will be commonplace.
In their recent paper, “How Will EPA’S Proposed CERCLA Hazardous Substance Designation of PFOA and PFOS Impact the Environmental Due Diligence Practice?” Jeff Marshall, PE, and Mike Miller, CHMM, discuss the anticipated impacts of the PFAS rule on environmental due diligence. Depending on the former uses, the number of RECs, and ESA results, some sites are more likely to feel the impact on the potential value of a property.
As our PFAS knowledge continues to evolve, so will applying this knowledge to the environmental due diligence practice and, ultimately, real estate conditions. Read the technical paper to understand the terminology and types of properties more likely at risk.
Jeffrey D. Marshall, PE – Vice-President. Mr. Marshall is a Vice President and the practice leader for the Environmental Services Practice for SCS offices in the mid-Atlantic region. He is also the SCS National Expert for Innovative Technologies and Emerging Contaminants. His diversified background is in project engineering and management, with an emphasis on the environmental chemistry and human health aspects of hazardous materials/waste management, site investigations, waste treatment, risk-based remediation and redevelopment, and environmental compliance/permitting issues. He has over 40 years of environmental experience and directs and manages environmental due diligence projects in the mid-Atlantic. He is a chemical engineer, Professional Engineer (VA, MD, WV, NC, and SC) and meets the credentials of an Environmental Professional.
Michael J. Miller, CHMM – Vice President. Mr. Miller is a Vice President and the practice leader for the Environmental Services Practice for SCS offices in the Central region. He also serves as an SCS National Expert for Environmental Due Diligence. He supports firm operations throughout the United States related to Phase I and II Environmental Site Assessments and the completion of large portfolios and complex site assessments. A Certified Hazardous Materials Manager (CHMM) since 2009, Mike has more than 28 years of experience in environmental management and consulting with an extensive background in RCRA-related matters and industrial compliance, planning, and permitting.
Additional Real Estate Resources:
Environmental justice is integrated into State and Federal environmental agency policy-making, thus impacting inspections and enforcement across the nation. While specifics are evolving quickly in each state, staying abreast of these basic requirements for the key environmental permits and plans listed here is best, especially if you have multiple facilities in multiple states.
We recommend this quick read to run through a checklist to decide if your facility is ready or may need an internal audit. For this article, we’re using Illinois and standard Federal requirements.
Being well-prepared for an inspection saves time and expense but will also support your company’s relationship with the regulatory agency and promote better outcomes and reduced risk of enforcement actions.
Deficiencies noted during an inspection can be a catalyst for additional inspections among non-EJ-located facilities.
Manufacturers in environmental justice areas denoted within each state can prepare for regulatory review and inspection by conducting internal or external audits of key environmental permits and plans to evaluate compliance with state and local regulations.
Additional Information: