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Writing Bar Screen Specifications for Quality and Competition

Duperon Corporation posted on August 06, 2019

How to Write Bar Screen Specifications for Quality and Competition

Consulting engineers have the important job of designing a specification that will support a long-lasting, effective, and affordable project. Unfortunately, in many cases, consultants have no control over much of the bidding and selection process, which can be problematic. When the final product doesn’t accurately represent the spec, the municipality and citizens suffer the shortcomings, and the consultant’s reputation is on the line. How can consultants avoid misuse of their spec, ensure that the best project is constructed, and protect their reputation while still adhering to lawful bidding processes?

Learn to write wastewater project specs more efficiently

Writing Municipal Projects for Quality and Competition

The bidding process plays a major role in how a project spec becomes a completed construction. But the effects of different bidding processes aren’t always clear at first glance.

Bidding processes are designed to encourage free and fair competition. However, this can inadvertently create a race to the bottom, where the bid with the lowest price wins, often at the expense of quality and functionality. In the case of essential systems, like wastewater treatment plants, this can create serious problems for cities and citizens, which reflect poorly on the consulting engineer. By understanding the bidding process in your area, it is possible to design a spec to mitigate these problems, and even prevent the use of deficient materials.

In this article, we’ll often refer to the example of a bar screen spec for demonstration. After all, Duperon knows bar screens best. However, this advice can apply to any spec that follows these bidding procedures, so feel free to consider the most applicable component spec for your circumstances.

Types of Bids

The types of bidding processes and, therefore, how a spec may be designed, are determined by state law. States generally allow several types of bidding procedures. While each state may make their own variations of these, most bidding procedures follow one of the following frameworks:

  • Conventional open bid
  • Base bid
  • Base/Substitute bid
  • Evaluated bid

Let’s explore each of these, and their implications on the spec and construction, in more detail using mechanical bar screens as an example.

Conventional Open Bid

The conventional open bid format is very common, and can be found in nearly every state. This style of bid was originally designed to stimulate competition and allow alternative solutions by requiring an “or equal” clause. This means a particular brand or type of equipment may be mentioned, but the “or equal” clause requires that brands or designs that meet the same specifications must also be equally considered.

While this style of bid does tend to create more competition, it has the unintended consequence of creating a price war. The “or equal” clause opens the field of possibilities too far, and the threshold for “equal” becomes unclear. This format also encourages other practices, such as post-bid shopping, which further prioritizes price over quality. Let’s consider a wastewater bar screen spec for example. Often, functionality, durability, cost of ownership and other factors which would concern the municipality become secondary to price. However, when this format produces unsatisfactory results, it is ultimately the consulting engineers and the spec that receive the blame.

When designing wastewater treatment facilities using the open bid format, engineers should be wary of equipment that appears “equal,” but does not meet quality, durability, or functionality requirements. If you were designing the spec for a bar screen, for example, you might want to consider the following:

  • Inferior materials: Equipment made from inferior materials will be lighter, and less robust. These may break down more quickly, and will not withstand heavy debris. A closer look at the equipment weight will show its durability, or lack thereof.
  • Maintenance: Though a system may appear more affordable at first, a more demanding maintenance schedule can quickly make it more expensive long-term. Look at the equipment’s average maintenance schedule on a daily, weekly, monthly, quarterly and annual basis. Be sure to consider costs of parts and labor hours as well as the risk of downtime to the facility. 
  • Energy costs: Energy costs can also quickly raise the long term costs of the equipment. Examine and require evidence for the equipment’s average energy use. 
  • Continuous operation: Can the equipment operate continuously without incident? This will be an important consideration. 
  • Warranty: How long does the warranty last, and what does it cover? The industry standard is 5 years. 
  • Installation: Assuring that an equal meets the performance intention of the specification, also consider how the equipment will be installed. Is modular assembly required?
  • Application experience: Verify that the equal has application experience with proven installations using the technology they are submitting.

How can consultants prevent a price war from affecting the functionality and longevity of the equipment needed? The first precaution is to make the spec as detailed as possible. This way, some inferior equipment or materials can be ruled out from the start. Engineers may accomplish this by listing specific performance metrics the equipment must meet, defining specific products or components, or by listing industry standards that must be met. Using the quality control clause, it is common to include a minimum number of installations that have been operating for five or more years. This reduces the risk of unknown or newer, unproven technologies from being submitted during the bid. Equipment that cannot meet these criteria can be eliminated.

In some cases, even with very detailed project specs, some equipment that is not functionally equal may slip through the bidding process. In these cases, the shop drawing phase will be especially important. However, debates at this phase put the bidding contractor under more pressure, and these disputes can become contentious.

Base Bid

The base bid format is also common and acceptable in most states. The base bid format differs significantly from the conventional bid format. This bid format is designed to remove inferior equipment from the process by selecting from a pre-approved list of suppliers and/or manufacturers. The consulting engineer and the owner generally design this list together. This gives the engineer and the owner more power in the selection process.

This list of suppliers and manufacturers can minimize the competition in the bidding process, but it can also prevent inferior products from entering the process. Consultants must take care to choose a fair and competitive selection that also presents good quality. In some cases, contractors may submit bids using materials or equipment outside the pre-qualified list, and may file a protest if they believe equal function and specifications have been met, but not approved.

To find the right suppliers for your wastewater treatment equipment using the base bid method, remember that the type of equipment is not the only concern. In many of the wastewater system specs we see, installation and application will have a significant impact on the system’s functionality. To ensure you receive the ideal system type or component for the application, set minimum requirements for years of experience, references, and the number of systems installed.

Using bar screens as an example, it’d be crucial for the spec designer to be aware that chain and sprocket systems, flexible multi-rake systems, and front-clean, rear-return systems will all have different installation needs and ideal environments. In this case, the design engineer might need to rely on a supplier’s experience to ensure the end result is the right system.

With this bid method, the consultant and owner have the most control over the project, and inferior bids are less of a concern. Pay close attention to transparency and fairness to avoid disputes and keep the project moving smoothly.

Base/Substitute Bid

This bid format is similar to the previous method, and seeks to expand competition while still using specific criteria to maintain quality. This method can be more complicated, and it’s important to pay close attention to state laws when using this method.

The base/substitute bid format uses the same process as the base bid, except it allows bidders to substitute materials or equipment that they believe meet criteria. There are two basic variants of this method, one where substitutions are considered after the contract is awarded, and one where substitutions are considered before.

In cases where substitutions are considered after the contract is awarded, the consultant and owner retain much of the control over the project and over potential substitutions. With proper consideration, low-quality substitutions can be avoided.

In the opposite scenario, consultants and owners are faced with a situation similar to that of the conventional open bid. This method again opens the bidding process to “equal” materials or equipment, and puts inevitable emphasis on price over quality and performance. In this case, similar to the conventional bid situation, consultants must take care to carefully define what constitutes “equal” materials or equipment. If these are arbitrarily selected, it not only introduces the potential for an inferior construction, but also invites debates and legal battles between all stakeholders.

If you were using a base/substitute bid when developing a bar screen spec, you’d want to consider the following requirements to fine-tune your spec and weed out low-quality equipment.

  • Shop testing: Equipment must be fully assembled and shop tested by the manufacturer before shipping. The owner/engineer reserve the right to review the shop test themselves. 
  • Previous installations: The manufacturer must have at least 25 installations of the equipment successfully installed and in use at comparable locations for at least 5 years. 
  • Specific system type: Specifying the exact system needed, including the design (chain and sprocket systems, flexible multi-rake systems, or front-clear, rear-return systems) as well as any additional features. 

Evaluated Bid 

In the evaluated bid format, bids are evaluated based on a point system. This method is less common, but can be found in Rhode Island, West Virginia, Florida, North Carolina, Texas and several others.

The point system used to evaluate bids are determined by the consulting engineer and owner. This again places a heavy responsibility on the consultant, but also confers an appropriate level of decision-making power. This point system may be based on the total lifecycle cost of the equipment or other metrics which make sense for the project.

The evaluated bid method is especially useful when there are several strong, viable suppliers, when the project’s design or performance affects other structures, or when performance can be quantified and measured on a comparative scale.

For this method to be successful, the formula and evaluation criteria for choosing a bidder must be clear. Bidders must be able to reasonably provide documentation proving they can meet these criteria. The verification process must also be clear, and this should be provided either through on-site testing, factory testing, or through performance bonds.

Though the exact determinations for the point system will vary between municipalities, there are several metrics which a point system may rely on, and which suppliers can prove that they meet. Again, we’ll use bar screens as an example. If a consultant were working on a bar screen spec, he or she would want to consider the following when developing a point system for an evaluated bid:

  • Energy costs: Using previous, comparable installations and environments, suppliers can show, on average, the energy costs their equipment demands on an annual basis. 
  • Maintenance costs: Again using comparable installations, suppliers can show the average maintenance costs their equipment demands, including work hours and materials. 
  • Lifetime costs: By combining the initial investment, energy costs, maintenance costs, and average lifetime, a points system may be based on the total costs across the system’s usable lifetime. 
  • Construction costs: Some technologies require different infrastructure, piping, concrete works, etc. Ensure these costs are factored in to the overall cost of the equipment, in addition to their purchase price to have a level playing field.
  • Customer references: Contacting a number of similar sites that utilize the proposed equipment is a great gauge of how it will work at your plant and what the manufacturer is like to work alongside.

This method gives the owner and consultant maximum control. The specifications used in the selection process provide strict criteria, and prevent the inclusion of inferior equipment. With these criteria, the evaluative formula and verification criteria all carefully considered and clearly stated, this bidding format strikes an acceptable balance between project competition and quality.

With a firm understanding of bidding methods, procedures, and rules, you can choose the best bidding type for the project, and work collaboratively with bidders instead of contentiously. This way, the bidding process and the competition can help to bring out the best and most affordable proposal for your client.

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Author: Duperon Corporation

Posted in: Products

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