Tank Maintenance and Rehabilitation Engineering
Tank maintenance engineering for a storage tank system involves four phases --- initial inspection or evaluation and tank washout, prioritization of tank maintenance requirements, preparation of plans and specifications, and quality control evaluation including contract administration. Having evaluated over 16,500 tanks for more than 2,650 water storage tank owners and operators, Tank Industry Consultants has an extensive database of problems associated with tank ownership. This background provides the basis for designing out future maintenance problems. In all, no other firm offers the expertise in tank maintenance engineering that TIC offers.
We do tanks.... ONLY tanks!
Tank Industry Consultants works closely with the owner/operator to establish operating goals and evaluate existing tank operating procedures. From this evaluation, TIC develops written guidelines for properly operating and maintaining the tank system for optimum performance and longevity. These guidelines are clearly written for use by the operating personnel and often replace the "word of mouth" operating instructions that lead to problems and additional costs.
The first step of a tank maintenance program is an engineering evaluation of the condition of each tank to determine its condition and what scope of work should be designed. Each inspection will encompass the actual on-site field evaluation, an evaluation of the roof and other structural members of the tanks, a coatings evaluation, and a safety and sanitary evaluation. Based upon the field evaluation, a certified engineering report is provided outlining the observations and recommendations for rehabilitation and maintenance or replacement to meet the objectives of the tank owner.
TIC performs all types of tank evaluations to meet each tank owner’s needs. There are currently three popular methods of inspecting tank interiors: a drained “dry” evaluation, an underwater evaluation performed by divers, and a robotic inspection.
The dry evaluation is unquestionably the most thorough evaluation and is often the least costly. Our specially trained technicians get to the necessary surfaces on the tank by rigging and rappelling the interior as required by the condition of each tank. During this dry inspection, the technicians get an overview of the entire tank interior, and can perform tests not suitable for underwater evaluations.
As an alternative when tanks cannot be drained or the tank owner prefers not to drain the tank, TIC provides underwater evaluations of tank interiors. Our diving evaluation includes a careful study of the tank's interior wet surfaces by our team of Certified Commercial Divers. Because the diver is also a member of TIC’s staff, averaging over 20 years inspecting tanks, the tank is evaluated by a highly qualified technician who knows what to look for, not a diver that takes random photographs. Our team members have been providing dive evaluations for the US Navy for more than 10 years. Our divers are trained to the stringent safety and high-altitude rescue requirements and procedures of the United States Navy. When performing an underwater evaluation, the diver utilizes a full dry suit and full-face diving mask to prevent contamination of the potable water. Prior to entering the tank, the diver and all equipment are thoroughly disinfected in accordance with AWWA C652-11. For safety reasons, the tank must be offline while the divers are in the tank. Taking the tank offline a few hours prior to the divers entering the tank will also improve visibility, as some of the sediment in the water will settle to the bottom. OSHA 29 CFR Part 1910, Subpart T - Commercial Diving Operations is the OSHA regulation that governs the dive evaluations within confined spaces. There are other industry standards, such as AWWA Standard 652 that can supplement plans for dive evaluations, but 29 CFR Part 1910, Subpart T is the criteria by which dive evaluations should be safely conducted. This is also the criteria by which fees, qualifications, or proposals for the dive inspection of water storage tanks should be evaluated. Some of the key principles include:
- Ensure that the company will comply with all OSHA Regulations when diving your tank. A recreational diving certification, such as PADI, is not an acceptable certification for diving tanks.
- The dive team size will be a minimum of 4 personnel, each with a commercial diving certifications. These dive teams are larger than a typical inspection crew because of safety concerns with diving in a permit required confined space. Two divers are required to be in the water and two additional divers are on the roof, acting as "tenders" to assist the divers.
- OSHA regulations require the tank systems be locked out and tagged out prior to a diver entering the water (29 CFR Part 1910, Subpart J - The Control of Hazardous Energy). This includes ensuring all valves are closed and any cathodic protection inside the tank is turned off.
- Hire an experienced company. A diver experienced with tank diving will be much more prepared for the hazards they encounter. Also, the diver should have relevant experience in inspecting tank structures, appurtenances, and coatings.
- Ensure the divers and all equipment will be disinfected and that the equipment has only ever been used in potable water.
The third type of evaluation TIC provides is a ROV inspection of the tank interior. This type of evaluation utilizes a robotic device, guided and monitored by one of TIC’s specially trained field technicians, to video tape the tank interior.
Similarly, our ROV is operated and guided by one of our trained technicians who knows the problem areas that need to be closely examined and who can "interpret" the video during the ROV evaluation to more closely evaluate areas of concern that would be overlooked by someone who was not intimately familiar with water tank design and maintenance. Prior to entering the tank, the ROV and all equipment are thoroughly disinfected in accordance with AWWA C652-11.
Regardless of the type of evaluation performed, our inspections are specially designed to uncover problems, and to look for methods to reduce rehabilitation costs.
As part of the standard evaluation and report, TIC identifies any observed structural deficiencies or damage that may have occurred since the structure was erected. Any deficiencies found will be analyzed for their affects on the structural integrity of the tank.
The recommendation section of the report includes those repairs and modifications required to bring the structure into compliance with present industry, safety, structural and sanitary standards and regulations. Also, coating recommendations will be made, as well as the recommended timing of the necessary coating repairs. When practical, alternative methods of repairs, modifications and painting will be provided. Advantages and disadvantages of each alternative will be given so the owner can determine their short-term and long-term tank maintenance requirements. Cost life analysis and comparative analysis of paints, coatings, and linings are continually being performed by TIC as new products and technology are developed for the coatings and lead-paint abatement industry. With more than thirty-nine years experience specifying tank coatings and having worked on over 16,500 tanks, TIC has extensive experience in determining which coatings best meet the short-term and long-term tank needs. This experience and expertise is utilized each time TIC evaluates another tank.
The economic factors section of the report provides budget estimates for all of the repairs, modifications, and painting requirements outlined in the recommendations section of the report.
With today's emphasis on infrastructure maintenance, the need for a method to rate and prioritize tank maintenance requirements has become increasingly evident. This is especially critical for municipalities, utilities, and industries with multi-tank systems. TIC has developed a computerized management tool for comparing the relative overall condition of structures within the same system that simplifies long-term maintenance prioritization. This rating and maintenance prioritization system also includes provisions for estimating the cost of the forecasted maintenance schedule. The condition rating and maintenance prioritization system TIC has developed not only integrates all of the above criteria, but also includes numerous other "user-friendly" characteristics.
Antenna Installation on Water Towers
With increasing NIMBY (Not In My Back Yard!!) concerns, cellular carriers are looking for existing structures--including storage tanks--to attach antennas to rather than building their own towers. This option also saves them money in land acquisition and tower construction costs, as well as future maintenance costs. Also, zoning restrictions may not allow the construction of cellular antenna towers. Many storage tank owners are leasing space on their towers, and some are constructing new tanks with the intent of providing access and points of attachment for initial or future antenna installation and service. However, as with everything else in life, there is a right way and a wrong way to do it, and a poor cellular antenna installation can create problems for the tank owner which can easily outweigh the financial advantages they provide. At TIC, we evaluate literally hundreds of tanks each year, and can assist tank owners in avoiding some of the typical problems encountered when antennas are installed improperly. In addition to structural, sanitary, and safety deficiencies that can be caused by improper antenna installation, there are also problems created which can impede or prevent future maintenance of the tank.
Most cellular companies have installations designed by their own engineers or consultants. However, our experience has proven that most designers and installation contractors have little experience with water tank design and even less experience in water tank maintenance. Therefore, simple items to prolong the life of the coating system or avoid potential sanitary, structural, or safety problems are often overlooked. While we're not suggesting that you take over the design responsibilities, it is prudent to have all plans, designs, and drawings reviewed by an independent third party whose only interest is protecting the water tank owner and who understands tank maintenance and design. Additionally, you should require site visits by the designer of record. Ideally, you would want periodic site visits to verify the work is being properly performed throughout the installation. Typical items requiring evaluation should include the proper installation of the antennas, brackets, and related conduit; removal of weld spatter; proper surface preparation and coating application; and quality of welds. At a minimum, a final site visit needs to be performed to check the installed product against the approved plans and drawings.
With any type of investment of this nature, a contractual relationship will be required between the cellular phone company and the water tank owner, and there are several contractual items that should be addressed. TIC has assembled a laundry list of considerations that owner’s should consider prior to entering into a contract. For a copy of this list, please contact a TIC office. (Note: qualified legal advice and direction should be obtained prior to entering into this type of contract.)
Observation of the Contractor's Workmanship
Resident observation of the contractor's workmanship is the most important part of a tank rehabilitation or new construction project. The best-written, most thorough specifications do not assure the project is completed correctly. TIC's technicians are experienced in tank repair, painting, and erection. They are not only familiar with proper coating application techniques, but also with the underlying reasons for tank painting standards. In addition, our entire staff of civil, structural, mechanical, and chemical engineers and support personnel, including our NACE Certified Field Services Manager, is available for supplemental technical support for any special problems that might occur.
Preparation of Specifications
TIC's specifications and contract documents will be more extensive than provided by most engineers' designs due to our experience and intimate familiarity with AWWA, NACE and SSPC Standards and how they must be supplemented. The specifications will be prepared in accordance with local, state, and federal laws, and all specific requirements of the owner. TIC enjoys working closely with our clients and values our clients' input. It is for this reason that we take the time to keep our clients informed and updated concerning the project's progress. After all reviews are complete, TIC will revise all documents as required for final approvals and prepare a final detailed cost estimate for the project. The project summaries, plans, and specifications will include the documents required to execute the project.
TIC assists the decision makers in analyzing the various methods of accomplishing the recommended repair and repainting options so that the long and short-term goals of the owner will be met. We share our expertise and knowledge of all applicable regulations, codes, and standards. While most engineering firms can provide a generic specification package, it is our uniquely developed specifications that address the work that needs to be performed. This reduces the change orders to only those items that have competitive unit prices already negotiated prior to starting the project.
Our specifications are not only designed to reduce construction costs during the tank rehabilitations, but also for future tank rehabilitation. By "designing out" problem maintenance areas, the newly applied coating system will not only last longer, but when future maintenance is performed, the repainting will be easier and therefore less expensive.
New Tank and Tank Rehabilitation Design
Tank Industry Consultants has evaluated over 16,500 existing tanks and has gained extensive insight into typical problem areas that often require a much higher degree of future maintenance in tanks. Meanwhile, most new tank contractors are not aware of these problems since they build the tanks and rarely see them again; and typical "general" consulting engineers do not have the practical experience and familiarity with construction methods of storage tanks to adequately deal with these problems. TIC utilizes this knowledge to "engineer out" these maintenance problems when the tanks are originally specified and designed.
Another advantage of having TIC involved with the preparation of new tank design and specifications is our involvement in the applicable standards committees. By assuming leadership roles on the committees that determine industry standards for tank construction, TIC is intimately familiar with the strengths and weaknesses of the pertinent standards. Even the best industry standard has gaps that need to be filled by a thorough and detailed technical specification. TIC is in a unique position to bridge these gaps with our experience and expertise.
Coating consulting is typically broken into three basic phases -- coating survey to determine the existing coating condition, coating system design to develop a coating system appropriate for the environment, and monitoring of the coating application to verify compliance with coating manufacturer's requirements. TIC has provided these types of services for all types of steel and concrete structures ranging from water tanks, clarifiers, lime silos, and digesters, to grandstands and even the roof decking on a natatorium.
Tank Industry Consultants has specialized structural engineering expertise in plates and shell structures, including tanks and vessels for a wide variety of applications:
- water storage and water treatment
- pressure / vacuum storage
- low temperature or cryogenic storage tanks
- secondary containment
TIC also is capable of evaluating tanks made of various materials (carbon steel, stainless steel, aluminum, concrete) exposed to normal and abnormal loads, which include seismic, high wind, projectile impact, shell stability, fire, extreme thermal loads, foundation settlements, and many other structural problems.
TIC is familiar with the requirements of US and international standards for tanks and vessels. TIC serves on many of the code development committees responsible for writing and issuing these standards.
TIC has experience in designing and planning seismic retrofit and modification to existing tanks for changes in service or operational parameters.
Seismic Evaluation and Retrofit Design
TIC personnel actively participate in developing the national provisions for reducing seismic hazards. Significant changes are currently being implemented in the methods of predicting the probability and magnitude of seismic occurrences, and the loadings structures must be designed to resist. TIC has the specialized expertise to apply these new rules to assess the structural system and recommend cost-effective alternatives for upgrading the system according to the applicable code or standard. TIC has designed several seismic evaluation, retrofit and upgrade projects for tanks of up to 16 million gallons in high seismic zones.
Leak Prevention and Secondary Containment Engineering
Many products commonly stored in tanks require secondary containment to prevent accidental release of the material that may expose the public or operating personnel to a hazardous material. The selection and engineering of the proper containment for specific applications may be complex. TIC assists owners/operators with the selection and design of liquid and vapor containment to meet regulatory and operating requirements.
Expert Witness and Dispute Resolution
Tank Industry Consultants is in demand throughout the country as an expert witness for various cases involving tanks. These cases--including failures, injuries, accidents, and pollution--allow Tank Industry Consultants to remain updated on potential liability problems and current court decisions. Here, lessons learned are used to improve the specifications that we prepare in order to protect our clients from similar problems.
In addition to the practical knowledge gained through hundreds of projects, TIC keeps informed of industry trends and standards through extensive involvement in standards-making organizations. In fact, TIC plays a significant leadership role in the development of these standards.
American Water Works Association (AWWA) - Steve Meier, one of TIC’s Managing Principals, chairs the AWWA Steel Tank Committee. In this capacity he oversees all standards development and revision processes for all steel tank standards including D100 (design and construction), D102 (coatings), D103 (bolted tanks), D104 (cathodic protection), D106 (sacrificial anode cathodic protection systems), D107 (composite elevated tanks), D108 (aluminum dome roofs), M42 (Tank Manual), and the proposed new stainless steel bolted tank standard. TIC’s engineering and technical staffs were extensively involved in authoring the AWWA Tank Manual (M42) and the Steel Water Storage Handbook to advise water tank owners from the planning stages of tank construction through tank demolition. Chip Stein recently updated the Manual at the request of AWWA. The Manual is now the benchmark for water tank evaluations, replacing the former D101 Standard. We know the recommendations contained in this Manual because we wrote them.
Chip Stein was recently named Chair of the D101 Standard Subcommittee for Inspecting and Repairing Steel Water Tanks, Standpipes, Reservoirs, and Elevated Tanks for Water Storage Revision Task Force and is a member of the AWWA D102 Committee on Tank Coatings, and a member of the AWWA D104 and AWWA D106 Committees on Cathodic Protection Systems. While other engineering and inspection firms list themselves as members of AWWA, TIC does more than pay dues and attend a few meetings. We donate hundreds of hours each year to providing leadership and expertise to facilitate the standards-making process so that water companies can continue to provide safe, clean drinking water to the communities they serve.
In addition to the leadership roles at AWWA, TIC’s Managing Principals are actively involved in a number of other industry organizations. Chip Stein is Past Chair of the STI/SPFA (Steel Tank Institute/Steel Plate Fabricators Association) Field Erected Steel Tank Committee, and served on the Editorial Advisory Committee for NACE International's publication, CoatingsPro. He is also a Principal Member of National Fire Protection Association (NFPA) Water Tank Committees NFPA 22 and NFPA 25.
Tank Industry Consultants is recognized by SSPC: The Society for Protective Coatings as a Certified Inspection Company. TIC is one of a few firms in the nation who have achieved this distinction. QP 5 certification offers owners the added assurance that the proper procedures are in place to perform inspection services with a high degree of quality. This level of quality was accomplished by TIC initiating quality programs that include regular training for field technicians, quality and procedural standards, corporate internal auditing on inspection records, and accountability.