Engineers Risk and Liability Considerations in Specifying Corrugated

Engineer’s Risk and Liability Considerations in Specifying Corrugated High Density Polyethylene (HDPE) Pipe Patricia D. Galloway, P. E. , Ph. D ACPA Short Course January 4, 2006

SO WHY DO ENGINEERS SPECIFY HDPE PIPE?

The “Hype” for HDPE “Pipe” n ADS n n n “HDPE is trusted by design engineers concerned with strength, durability, and safety. N-12 pipe from ADS-…and civil engineers increasingly specify it for demanding storm sewer applications. In retention/detention systems, highway drainage on site development, N-12 pipe simply outperforms traditional concrete or steel pipe. ” “can be installed two to three times faster than concrete pipe…its light weight means more pipe per delivery, easier handling, and small crews. From design to completion your projects arrive ahead of schedule. ” “In thousands of uses, from depths of one foot to over 100 feet, ADS pipe has proven to be efficient and longer lasting than concrete or metal. And installation is easier and faster. ”

The “Hype” for HDPE “Pipe” n Plastics Pipe Institute n n “Because of HDPE’s resistance to abrasion and chemicals, polyethylene pipe’s life-cycle savings over alternative drainage systems are significant. Users can expect a minimum service life of 100 years in many typical drainage applications. ” “Silt tight and water tight joints mean that what’s inside the pipe stays inside the pipe, keeping communities, citizens, groundwater systems and wildlife safer and more secure in their environment. ”

The “Hype” for HDPE “Pipe” n Plastics Pipe Institute continued: n n n With proper installation and operation, a 100 -year life can be expected Corrosion-free Smoother flow than corrugated metal or concrete-prevents build up of silts and sands to reduce maintenance needs Flexible but tough Lightweight for easy handling Superb resistance to chemicals and to abrasions Impact Capacity-virtually eliminate breakage due to freezing pipes Full range of pipe sizing and fittings Soil tight, silt tight and water tight joints Can be transitioned with existing pipe Proven in wide range of applications for 30 years

The “Hype” for HDPE “Pipe” n Plastic Pipe Institute n n Polyethylene has a superior weight-to strength ratio Polyethylene has 60% fewer joints than RCP Polyethylene is the most chemical resistant of the three piping alternatives ADS n “The U. S. Forest Service-to whom fire is an obvious and great concern-has approved PE pipe for culverts and other drainage applications…. . Fire damage has not been a problem. ”

The “Hype” for HDPE “Pipe” n Soleno n n n Economical Easy to handle Light Resistant Strong Safe n Soleno n n n Flexible Easy to assemble Easy to transport Easy to cut Easy to perforate Superior flow

The “Hype” for HDPE Pipe n Armtec-Boss 2000 and Poly-Tite n “at less than 10% the weight of concrete pipe …BOSS pipe affords the contractor these important benefits”: “Savings on installation”: … “Less manpower and lighter machinery”… n “Faster installation”: six metre lengths are easily handled using minimal equipment…can be installed nearly 25% faster than the same diameter concrete pipe”… n “Safer handling”: … n “Quick on-site cutting”: …”can be trimmed to length in seconds” n

SO WHY NOT SPECIFY HDPE PIPE? No reason-as long as you know and understand the facts, the risks and liabilities associated with the engineering decisions that you make and the design that you prepare, review and/or approve.

Plastic Pipe Institute Ad “As an engineer I have no patience for failing pipe. I want proven engineered solutions. ” AN ACCURATE STATEMENT Who Has Design Responsibility? What is Considered Proven?

The Engineer’s Role n n n Any time an Engineer designs a project, any error or mistake could result in either property damage, personal injury or death. The Order of the Engineer as well as Professional Society Codes of Ethics and State Licensing Boards define the Engineer’s role and responsibility. In general, the Responsible Engineer’s role in any design project is to design a project that meets the desired purpose, is constructible, and is designed so that the user and public health, safety and welfare protected. If the design is found to be faulty and there is injury-to either property or person, or the Engineer is found not to have followed the Standard of Care-the Engineer can be held liable and even negligent. Being held liable, failing to meet a Standard of Care and/or having been found to be negligent and causing damages will result in monetary damages, and in some states, potential loss of license and where death occurs, potential criminal charges.

Definitions Critical for Engineers to Understand n n Liability Standard of Care Negligence Duty

Liability n n n An obligation that one is bound in law or justice to perform Condition of being actually or potentially subject to an obligation Condition of being responsible for a possible or actual loss, penalty, expense or burden

Liabilities Affecting the Engineering Professional n Standard of Care n n Negligence n n Failure to perform as others would reasonably do in the same conditions Failure to do what is reasonably required Contractual n Failure to fulfill an obligation required by contract

Standard of Care n Standard jury instructions of standard of care: n n n “In performing professional services for a client, defendant has the duty to have that degree of learning and skill ordinarily possessed by reputable engineers practicing in the same or a similar locale and under similar circumstances” “It is his or her further duty to use care and skill ordinarily used in like cases by reputable members of his or her profession practicing in the same or similar locality under similar circumstances, and to use reasonable diligence and his or her best judgment in the exercise of his or her professional skills and in the applicability of his or her learning in an effect to accomplish the purpose for which he or she was employed. ” “A Failure to Perform Any Such Duty is Negligence”

Negligence n n The failure to use such care as a reasonably prudent and careful person would use under similar circumstances Doctrine of negligence rests on the duty of the engineer to exercise due care in his/her conduct towards others from which injury may result

Elements of Negligence n n Injury (damage) To a party That is reasonably foreseeable And where there was a duty owed to the injured party

Duty-to Whom it is Owed n n n The public-by statute or Code of Ethics Employer Customer Consumers Those whom we reasonably know may be affected by our decisions

Insurance Will Not Protect n Professional Liability Insurance typically does not provide coverage for product type liability exposure (i. e. specifying a product upon which you have assumed and relied will perform)

Engineers Are Bound Ethically and Legally n n n Order of the Engineer ASCE Code of Ethics Individual State Licensing Administrative Codes of Law

Order of the Engineer n n n n n AS AN ENGINEER, I PLEDGE TO PRACTICE INTEGRITY AND FAIR DEALING, TOLERANCE AND RESPECT, AND TO UPHOLD DEVOTION TO THE STANDARDS AND THE DIGNITY OF MY PROFESSION, CONSCIOUS ALWAYS THAT MY SKILL CARRIES WITH IT THE OBLIGATION TO SERVE HUMANITY BY MAKING THE BEST USE OF EARTH’S PRECIOUS WEALTH. n n n n n AS AN ENGINEER, I SHALL PARTICIPATE IN NONE BUT HONEST ENTERPRISES. WHEN NEEDED, MY SKILL AND KNOWLEDGE SHALL BE GIVEN WITHOUT RESERVATION FOR THE PUBLIC GOOD. IN THE PERFORMANCE OF DUTY AND IN FIDELITY TO MY PROFESSION, I SHALL GIVE THE UTMOST.

ASCE Code of Ethics n Fundamental Canon 1. 0 n “Engineers shall hold paramount the safety, health and welfare of the public…. a. Engineers shall recognize that the lives, safety, health and welfare of the general public are dependent upon engineering judgment, decisions and practices incorporated into structures, machines, products, processes and duties. n b. Engineers shall approve or seal only those design documents reviewed or prepared by them, which are determined to be safe for public health and welfare in conformity with accepted engineering standard. ” n

Texas Administrative Code n n a) Engineer shall be entrusted to protect the health, safety, property, and welfare of the public in the practice of their profession… b) Engineer shall not perform any engineering function which, when measured by generally accepted engineering standards or procedure, is reasonably likely to result in the endangerment of lives, health, safety, property or welfare of the public.

Delaware Administrative Code n The Engineer shall hold paramount safeguarding life, health, and property and promoting the public welfare in the performance of his professional duties.

Responsible Party n Example telephone conversation to Engineer who had specified HDPE pipe: n n n Lawyer: “The first things we’re going to need is a copy of your original design calculations for the crossing so that we can send them to our expert for his review”. Engineer: “Design calculations? I know my associate must have done them, but I don’t remember reviewing any design for the pipe crossing. I do remember the box culvert because we changed the wall thickness to save money and had to recalculate all of the steel areas, but the designs on the plastic pipe… I really can’t recall ever looking at anything other than the trench detail. Lawyer: “We’ll also need the soil study, the installation details and the inspection logs. ”

Responsible Party cont. n n Engineer: “I know we used a soil study in designing the base for the roadway, but for the pipe? Installation and inspection shouldn’t be a problem, we use the same procedures for the plastic pipe that we use for concrete pipe and the contractor liked the plastic better because he said it not only went in faster, but saved us about 10% in material cost. Anyway, our inspector was on the job, so I’m not concerned about his logs. Lawyer: “Notify your insurance company because they may want to defend this case themselves. Just in case, you also may want to consult a criminal attorney for yourself. My expertise is only in tort law and I’m afraid you're in this fairly deep. ”

Responsible Party cont. n Engineer: “ As my jaw dropped and the blood drained from my head, I couldn’t decide whether to laugh or cry. My entire career, my business, my reputation, everything I’ve worked for could go down as quickly as that pipe had collapsed under the highway. Fortunately, the state trooper told me no one was killed, although two cars fell into the hole where the pipe had collapsed. There were injuries, but all had survived. It couldn’t have been my fault. ”

Fiction? No-Reality n Failures of HDPE pipe have been increasing throughout the United States n n n 1999 -Houston, TX-City of Houston installed 1, 000 ft of 42” and 48” HDPE pipe as demonstration project. Two years later found major distress with excessive deflections, walls torn and buckled and joints were permitting intrusion of embedment material. 1999 -Minnesota-HDPE drain pipes have distorted and even collapsed. Attributable to installation methods. Baltimore, MD-2001 -Parking lot collapse-inferior drainage pipe material Williamsburg, VA-1999 -60” dia storm drainage system under 3 ft of earth. Within 1 year severe deformation in excess of 13%, joint separation, buckling and corrugation. Huntington, WV-1999 - hospital parking lot-RCP changed to HDPE due to cost savings of $10, 000. 4 years later HDPE failed and caused parking lot to fail-replaced with RCP. Pataskala, OH-2002 - Real estate development delayed due to failure of HDPE storm drainage outlet pipe. Bedded on stone and backfilled with native material. Failure included wall crush, excessive deflection, partial collapse, open joints and cracking.

Failures Cont. n n n n Saukville, WI-parking lot drainage pipe floated out of part of the parking lot-had only 1 foot cover-fortunately pavement not yet completed St. Paul, MN-ditch realignment-24” -2 ft cover-floated out of the ground after a day of steady rainfall. Chattanooga, TN-48” dia drainage pipe floated out of ground 3 times even though covered 12 “. When developer revealed plans to use HDPE pipe in lieu of concrete pipe, Engineer asked to be released in writing of any liability and responsibility. New Braufels, TX-2 lines of 24” dia with 1 ft cover under pavement floated on end of street after heavy rainfall uplifting street pavement. Timonium, MD-4 -year old 48” dia collapsed in Lowe’s parking lot at a cost of $500, 000 to replace Pelham, AL-After a few years in new subdivision, 42” and 48” dia collapsed in backyards between homes-had 3 -7 ft of cover Elmore County, AL-24” dia. Collapsed in new subdivision street causing sinkhole-it was had been installed only 2 years earlier.

Engineers/Manufacturers Sued n Shell Lake, Wisconsin n Failure of HDPE drainage pipe resulted in: n n n Ridge Line Inc, West Virginia n n n Flooding and severe damage to 120 of the lake’s 380 residences A declaration of a state of emergency for the Shell Lake area by the Governor of Wisconsin A class action suit by the residents against the design engineer, the pipe manufacturer, the contractor, and the City of Shell Lake The recommendations for repair could take up to 2 million and 12 months to complete Development-Developer chose to use HDPE for “cost savings” Engineer had specified 48” PVC pipe Collapsed after 6 years Relining did not work Now replacing City of Pueblo-Department of Public Works n n Significant failure of HPDE used for portions of storm sewers in subdivisions Will no longer allow HDPE to be placed in any of the City’s public ROW

Why Do Some Engineers Find Themselves in Trouble? n n n Failure to understand and/or perform life-cycle cost analysis Failure to recognize and understand the differences in pipe design, installation and inspection between HDPE and concrete pipe Assumption that HDPE is merely a substitute product for concrete pipe “Enamored” by HDPE pipe manufacturer literature and alleged “benefits” over concrete pipe Reliance on HDPE Manufacturer literature Assumption that he or she is “bullet proof” and that design is protected either by its own professional liability insurance or that issues arising at the site are problems solely the result of manufacturer or contractor issues

Will Engineers Be Protected by Manufacturer’s Literature and Warranties? n n NO!!!!!!! READ THE WARRANTY INFORMATIONMost Engineers are VERY surprised

Lane Enterprises, Inc. Warranty n “Material furnished to the Buyer shall conform to applicable ASTM and AASHTO standard as to materials, workmanship and tolerances. THIS WARRANTY IS MADE IN LIEU OF THE OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTY OF MERCHANTABILITY, THE IMPLIED WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE, AND ANY IMPLIED WARRANTY ARISING OUT OF A COURSE OF DEALING OR OF PERFORMANCE, CUSTOM OR USEAGE OF TRADE, EXCLUSIVE OF TITLE. ”

Hancor Warranty n “We warrant our products to conform to any system furnished by us in writing to be free from defects in material and workmanship under normal use and service. Improper installation or use, or any unauthorized repair, modification or alteration of our products will void this warranty. We make no guarantee of the results offered for the use of our products…. claims must be reviewed by us within one (1) year from the date of shipment…. . IN NO CASE WILL WE BE LIABLE FOR REMOVAL OR INSTALLATION COSTS, DOWNTIME, DAMAGE TO PROPERTY, LOSS OF BUSINESS OR PROFIT, OR ANY OTHER CONSEQUENTIAL, INCIDENTAL, OR SPECIAL DAMAGES EVEN IF WE HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. ” “Even if we offer directions, recommendations, or suggestions for the use of the products, it is solely Buyer’s responsibility to determine whether a product is suited for the specific needs of the Buyer, and there are no representations or warranties except as set forth herein. Buyer assumes all risks and liabilities arising from unloading, discharge, storage, handling, installation, and use of our products…. . ”

NOT UNDERSTANDING A PRODUCT WHILE ALLOWING ITS USE AMOUNTS TO NEGLIGENCE

Familiar Engineer Responses n n “No one said it was different” “No one said to read the specifications to be incorporated” “No one told me it was not a structure” “No one told me it was only a liner”

The Engineer’s Responsibility in Specifying HDPE Pipe n n n n Know the differences between HDPE and Concrete pipe Determine who the manufacturers are Read and understand the manufacturer literature-distinguish ad “hype” from the actual manufacturer facts on their product Recognize that HDPE pipe is not a structure and not the same as concrete pipe-the design requirements are different. Understand the Standard Specifications of ASTM and AASHTO Recognize that the installation of HDPE is an engineered installation and that the Engineer MUST take an active role in both design and construction Inspection required post project completion-The Engineer will never be divorced from the decision if made to use HDPE pipe Analyze the life cycle costs and risks associated with the pipe product chosen

What Are the Differences Between HDPE and Concrete Pipe? n Rigid n n n Load bearing structure Load transfer down Structure designed , built and tested is the pipe Structure arrives on the truck Not very soil structure dependent Trenches have little effect on structural capacity of product n Flexible n n n Load transfer to side support soil Must deflect to function Prime structure is soil Soil dependent Structure built and tested in the field Designers must calculate the width of the trench required to provide sufficient structural strength for the system. This determination should be made by a soils expert

Manufacturer Literature n n Many manufacturers in their literature “remind” the Engineer of his/her design responsibility and the limitations of HDPE pipe: Fratco n n n Prevent tubing damages during backfill Select proper materials The manner of use determines the depth of cover Service and longevity depend on creating a proper bedding Effective drainage results from proper grade

Manufacturer Literature n Lane Enterprises n n “HDPE is a flexible pipe, therefore it is dependent on the soil-structure interaction to achieve its structural performance level. As a flexible pipe, HDPE will deflect until the passive lateral pressure of the backfill restrains further deflection. The soil provides the stiffness to a flexible pipe. This means the performance of HDPE pipe improves as the quality of the backfill material and compaction improve. ” “The use of proper backfill material and good compaction techniques are critical when installing HDPE pipe. HDPE is a flexible pipe material and relies on the bedding and backfill material for its strength. ”

Manufacturer Literature n ADS n “Successful installation of flexible and rigid pipe are dependent on quality material and on proper design, backfill and installation. ”

Prudent Risk Analysis as per Crumpler Plastic Pipe n “When an engineer analyzes a storm water drain site there are numerous and complex factors to consider before selecting a pipe material or materials from the many pipe materials available today. Phase I of the selection-elimination process would be to determine the size of pipe or pipe needed to carry the 20 -50 -100 year projected storm flow of a particular site….

Prudent Risk Analysis cont. n n …the Phase II step would be to perform a Life. Cycle-Economic Cost Analysis. The engineer would consider the chemical characteristics of the liquid flow, sediment load in the flow and the soil properties along the drain feed and main lines…. The engineer is looking for Durability. …. Phase III is the selection-elimination process. Risk Analysis is the quantification of the exposure, vulnerability and probability. It involves the evaluation of alternative means to reduce risk and the determination of acceptable levels of risk.

The Standard Specifications n n n n n AASHTO M 252 -spec for CPP 3”-10” AASHTO M 294 -spec for CPP 12”-36” AASHTO Section 18: soil-thermoplastic pipe interaction system AASHTO Section 12: buried structures and tunnel liners AASHTO Section 30: thermoplastic pipe ASTM D 2321: Standard practice for underground installation of thermoplastic pipe for sewers ASTM D 3212: Standard spec for joints for drains and sewer plastic piping ASTM D 3350: Standard spec for polyethylene pipe and fitting material ASTM F 477: Standard spec for elastomeric seals (gaskets) for joint plastic pipe

ASTM D 2321 -04 n “For pipe larger than 12 inches (300 mm), the engineer should establish the minimum embedment width based on an evaluation of parameters such as pipe stiffness, embedment stiffness, native or in -situ soil, and magnitude of construction and service loads. ”

ASTM D 2321 -04 n “XI. 1 Those concerned with the service performance of a buried flexible pipe should understand factors that can affect this performance. Accordingly, key consideration is the design and execution of a satisfactory installation of a buried flexible thermoplastic pipe that provided a basis for the development of this practice are given in this Appendix”

ASTM D 2321 -04 n n n XI. 2: General subsurface conditions should be adequately investigated prior to construction XI. 3: The design, specification and construction of the buried flexible pipe system should recognize that embedment materials must be selected, placed, and compacted so that pipe and soil act in concert to carry the applied loads without excessive strain from deflections or localized wall distortions. XI. 4. 1: Construction loads must be addressed in the design XI. 10: Engineer responsible to see proper trench width specified and consider all aspects of pipe installation, pipe thickness, embedment stiffness XI. 13: Deflection Testing: To ensure specified deflection limits are not exceeded, the engineer may require deflection testing of the pipe using specified measuring devices. To allow for stabilization of the pipe soil system, deflection tests should be performed at least 30 days after installation….

ASTM D 2321 -04 n Recommendations for incorporation into contract documents (for flexible pipe) n n n Embedment and backfill materials Specific granulation of embedment materials Maximum particle size Restrictions on mode of dewatering, design of under drains Minimum trench width Restrictions or details for support of trench wall Restriction on method of compaction Minimum embedment density Minimum cover Inclusion of testing for compaction and leakage Requirements on deflection and deformation measurements, including method and time of testing

AASHTO Bridge Committee-Technical Committee T-4 Construction/T-13 Culverts-Revised 6/28/05 n n n n Added inspection of thermoplastic pipe Working drawings-added substantiating calculations Drawings are to be approved by the Engineer Inspection for proper installation for proper performance Final inspection to evaluate long-term performance-conducted no sooner than 30 days after completion, installation and final fill Pipe should be evaluated to determine whether internal diameter of barrel has reduced more than 5 percent when measured not less than 30 days following completion of installation. Pipe checked for deflection using mandrel-shall be sized and inspected by Engineer prior to testing.

What Authorities Have Researched and Found n TRB-Study of Culvert Failures-11/03 n n n Service Life: for a major infrastructure project, designers should use a minimum project service life of 100 years Plastics: Performance history limited. A designer should not expect a product service life of greater than 50 years. KYDOT-2005 -7 HDPE sites-age: 2 -15 yrs n n Significant change in deflection since testing at completion. Most > 10%: Evident that several pipes continue to deflect after installation Radial cracking, invert and crown flattening, racking and sagging observed: Evident that radial cracking occurs after installation Specifications should ensure correct bedding and backfill requirements, proper densities and proper compaction efforts are adhered as outlined in ASTM D 2321 and AASHTO Section 30 Additional laser testing recommended for long-term performance analysis

State Recognition of Deflection Issue n n n GA: Min 25% of pipe system mandrel tested any pipe over 5% deflection be removed and replaced KY: Reduces condition of payment by up to 50% where inferior installation causes the pipe to deflect beyond the 5% deflection limit WI: Requires min 10% system mandrel tested any pipe >5% removed and either reinstalled if not damaged or replaced at no cost IL: Mandrel test system 30 days with pipe >5% deflection NV: Pipe not exceed 5% vertical deflection limit after 30 days and does not allow “rerounding” of pipe that does not meet the test.

Conclusions n n n Concrete and HDPE pipe are not the same and not alternates to each other Concrete pipe trenches are not designed for plastic pipe Using other’s specifications and literature doesn’t relieve you of your design responsibility Soils are different at every jobsite If specifying plastic pipe, Engineer must be at jobsite to oversee installation as the structure is designed and tested in the field Only way to determine if a structure has been built according to your specs is through mandrel testing of the entire system n n n If a deflection of > 5% Fails Require no sooner than 30 days after backfilling and again prior to the surrender of the performance bond (12 months) Engineers design, specify, require and ENFORCE The Engineer has a sworn duty to protect the public health safety and welfare Forgetting any of the above results in the Engineers assuming the role of the Responsible Party with all the risk, liability and consequences thereto.