UAA Best Management Practices for Closed Chain of Custody for Herbicide Use

UAA Best Management Practices for Closed Chain of Custody for Herbicide Use

June 26, 2013
The UVM industry creates a best management practice for adoption of a closed chain of custody for herbicide use.

The utility vegetation management industry uses herbicides extensively to maintain vegetation on electrical utility rights-of-way. Herbicide use helps to keep rights-of-way (ROW) free from tall-growing tree species that might otherwise pose a risk to power system reliability. Maintaining ROW vegetation also helps to ensure access for inspections, maintenance and emergency repairs.

A closed-connect drum to backpack combo.

Traditionally, herbicides used in utility vegetation management (UVM) have been supplied in concentrated forms, in non-returnable containers. This requires mixing and loading open containers of concentrate on job sites. Advances in chemistry and application methods have significantly reduced the volume of herbicide solutions applied. Low-volume application techniques and herbicide formulations have made it practical to adopt ready-to-use and diluted concentrate formulations in closed delivery systems — a practice that further protects the applicator and the environment. Not only is the applicator’s safety enhanced, but utilities can save time and money by using closed delivery systems.

However, until recently, only limited attention has been focused on the logistics of shipping, storing, mixing and handling of herbicides, as well as managing the waste stream, including rinsates and empty containers. The Utility Arborists Association (UAA) saw both a need and an opportunity to demonstrate leadership by developing a best management practice (BMP) focused on a state-of-the-art strategy for managing the chain of custody for herbicide use — from producer to distributor and custom blender, through applicator to application — on a ROW. The BMP also addresses the handling of empty supply containers.

The UAA believes this BMP is a demonstration of proactive industry self-regulation and a clear demonstration of the UAA’s commitment to environmental stewardship.

Closed Chain of Custody

The new UAA BMP establishes an end-to-end strategy, or closed chain of custody, for managing herbicides through the UVM supply chain. This chain starts with producers of herbicide products to distributors and, potentially, custom blenders. The chain then extends to applicators and utility owners of transmission and distribution ROW. It also includes the return and reuse of empty containers. Said another way, the closed-chain-of-custody concept includes herbicide formulation, shipping, distribution, storage, mixing and application. It also includes the return of empty containers for refilling and reuse. The BMP is intended to increase the level of professionalism and environmental stewardship demonstrated by UVM programs.

There are four important elements to the closed chain of custody:

  1. The container cycle — supply containers that are returned, refilled and reused
  2. The integrity cycle — closed connections at the transfer points between supply containers, mix tanks and application equipment
  3. The documentation cycle — a container tracking system that establishes an auditable record documenting the movement of herbicides and containers
  4. The herbicide cycle — herbicide formulations delivered as custom blends that contain active ingredient and any necessary adjuvants.

The use of closed, reusable containers in the UVM industry can be traced back to the pioneering efforts of West Penn Power, now part of Allegheny Power, and its UVM contractor service providers in the mid-1990s. The concept was initially developed as a means of improving inventory management. Subsequently, applicators recognized the potential for productivity gains. That is not to say the early adopters had an easy time with it. Fortunately, the known problems have been addressed in developing the current state of art, which is centered on the use of custom blends provided in returnable, refillable closed-supply containers.

Returnable, Reusable Supply Containers

Reusable closed-supply containers are easy to refill.

The BMP promotes the use of supply containers that are returnable, reusable and, ultimately, recyclable. There are inherent advantages associated with this concept. The supply containers are filled by custom blenders and are the vessels in which custom blends are provided to the applicator.

These robust supply containers reduce the likelihood of leakage from container damage. Also reduced is the risk of regulatory non-compliance, such as the application of off-label rates or improper disposal of rinsates and empty containers.

Closed Connections

The BMP is intended to promote the use of closed interlock valve connections at each transfer point, where herbicide is being moved from one container to another container or tank, including application equipment supply. There are advantages with the use of returnable, reusable closed-supply containers.

Maintaining closed connections at transfer points throughout transportation, filling and application reduces personnel exposure to concentrated herbicide products. Closed connections at transfer points also may reduce the likelihood of leaks and spills during handling, mixing and loading.

There is a closed connection between supply container and the applicator’s equipment.

Tracking and Record Keeping

The BMP provides for an auditable record documenting the movement of herbicides and containers through the chain of custody, from producer to distributor, to custom blender, to utility, to applicator and back to custom blender (with the return of empty containers).

Custom Blends

Containers are marked for measuring quantities of custom blends.

The BMP promotes the use of custom blends, which reduce the potential for measuring errors during loading and mixing. This comes from the combined strategies of using blends in the required ingredients and the use of closed connections. Together, they help to ensure the correct concentration of spray mixture, including active ingredients, diluents and adjuvants are being used. As a result, the potential for errors, omissions and unauthorized changes in amounts or products is eliminated. When custom blends are supplied in volumes that match spray tank requirements, the need for measuring can be eliminated, just as they are for ready-to-use products.

Utilities and applicators that focus on a few basic core mixes for their specific programs and projects are more likely to realize the full benefit of returnable, reusable closed-supply containers. The intent of the BMP is to encourage increased standardization within individual operations. The BMP also acknowledges the need for an adaptive UVM strategy that anticipates the need to make changes in application-ready mixtures at the time of application as a result of changing weather or site conditions.

Benefits of the BMP

There are sound operational reasons for adoption of the practices described in the new UAA BMP. Maintaining closed connections at transfer points throughout the transportation, filling and application system, as herbicides move from supply containers to mix tanks and application equipment, reduces the handler’s and applicator’s exposure to herbicides. The use of custom blends of diluted concentrates and ready-to-apply formulations reduces potential exposure to concentrated herbicide products.

The use of all-inclusive custom blends of diluted concentrates reduces the likelihood of errors in measuring the proper quantity and during mixing operations. It also ensures the integrity of the intended formulations, including active ingredients, diluents and adjuvants by reducing the likelihood of unauthorized changes in rates or substitutions. When diluted concentrates are supplied in volumes that match spray tank requirements, the need for measuring can be eliminated, just as they are in the case of ready-to-apply formulations.

The use of returnable, reusable supply containers reduces the volume of the waste stream associated with UVM operations. Firstly, the number of one-way containers that must be disposed of in a landfill is reduced. Secondly, there is a reduction in the volume of rinsate generated by a spray crew because returnable, reusable supply containers eliminate the need for triple rinsing empty containers before refilling. The volume of rinsate generated by the use of conventional, open one-way disposable containers is significant, though it can be reused as part of the diluent in the next batch of mix being prepared.

Provisions within the BMP also are an effective means of risk mitigation. The use of closed connections at transfer points may reduce the likelihood of leaks and spills during handling, mixing and loading operations. The use of robust returnable, reusable supply containers reduces the likelihood of damage, resulting in a leaking container. There also is a reduction in the risk of unintended regulatory noncompliance, either because of the application of off-label rates or improper disposal of rinsates and empty containers.

Anecdotal evidence of the benefits of many of the practices within the BMP was identified in discussion with stakeholder groups. For example, crew personnel that had used custom blends in reusable closed containers were reluctant to return to the use of open one-way containers, and applicators that had incorporated the practices in their operations brought them to work on other utility systems.

The Financial Assessment

While the operational benefits of the BMP have become clear to practitioners, financial analysis has confirmed the closed chain-of-custody BMP is cost-effective. The costs and benefits of the BMP were compared with the traditional approach where disposable one-way containers are used to ship herbicide concentrates and mixing was performed on job sites. The results from this analysis demonstrated there is a financial incentive to migrate to the improved methodology.

The financial analysis of the economic implications of implementing the new closed-chain-of-custody BMP was broken down into four previously described elements:

  1. The use of returnable, reusable supply containers
  2. The use of a closed system
  3. The use of an improved means of tracking supply containers
  4. The use of custom blends versus concentrates.

The financial analysis was conducted in such a way that the cost of implementation and financial justification for each element could be considered a separate initiative.

The economics for each initiative were examined and calculated, as appropriate, for the aggregate of all stakeholders (utilities, distributors, custom blenders and applicators) into a supply-chain-wide five-year net present value (NPV). The key reference metric is the cost differential of a mixed ready-to-apply gallon in a spray tank. This was a calculation made by comparing the traditional use of packaged goods in open one-way containers with the corresponding element in the closed-chain-of-custody BMP.

The five-year NPV, given a yearly cost of capital of 9% (the cost of capital is an average for 2009 taken from various asset owners, distributors and custom blenders), is presented individually and in composite in the table for each of the four aspects of the closed-chain-of-custody BMP.

Closed Chain of Custody BMP Five-Year Net Present Value Results Per Applied Gallon
Application type Returnable, reusable supply container Returnable, reusable supply container Returnable, reusable closed supply container Tracking Custom blend All CCC BMP elements
RTA: Low-voltage basal $1.13 $(0.64) $0.49 $0.07 $0.25 $0.81
DC: Low-voltage foliar $0.08 $0.00 $0.08 $0.00 ($0.04) $0.04
DC: High-voltage foliar $0.04 $(0.01) $0.03 $0.00 $0.01 $0.04
DC: Aerial $0.12 $(0.05) $0.07 $0.02 $0.42 $0.51

Table. Closed-chain-of-custody (CCC) best management practice (BMP) five-year net present value results per applied gallon.

The adoption of returnable, reusable supply containers is net positive across all four application types. This is because of the two main contributing factors: the avoided cost of proper disposal of one-way containers and the incremental improvement in crew productivity related to the efficiency of transferring and mixing herbicides.

The adoption of closed connections comes at a premium. There is an immediate benefit from more accurate herbicide mixing, thereby reducing waste as well as spillage-induced liability, but it is countered by the initial capital cost to refit herbicide application equipment. However, when combined with returnable, reusable closed-supply containers, the benefits are net positive.

Improvements in tracking are economically positive, primarily because of better inventory management. There also are savings in the purchase cost of formulations such as custom blends, except in the case of low-volume foliar applications. When all elements of the closed-chain-of-custody BMP are considered together, the results are net positive, as reported in the right-hand column of the table.


Financial analysis conducted as part of this project demonstrates this new BMP can be adopted at no additional cost to the UVM industry. To be clear: the analysis was conducted at the UVM industry level, which considered the net cost to all parties in the supply chain. It is likely that, at least in the short term, there will be inequity in the costs and benefits among various stakeholders in the process, as some bear costs in excess of any direct benefit they might receive. However, in an efficient marketplace, any initial unintended cross-subsidization would be reconciled, as costs and benefits true up.

Technical specifications for the BMP are available from the UAA, as is a copy of the project report that describes the investigation and process used to develop the BMP. The technical specifications are intended to be easily adopted by utilities, by referencing it in UVM procurement specifications. A field handbook for crews is available from the International Society of


The UAA analysis demonstrated that adoption of the BMP can reduce the risks of mixing errors and spills, as well as applicator exposure. Adopting the BMP is a demonstration of good environmental stewardship.

Perhaps the strongest evidence for adoption is anecdotal. Application crews that have used custom blends in returnable, reusable closed-supply containers like the practice and are reluctant to return to open containers. Applicators that use them have brought the practice to work on utility systems where they have not been used.

The BMP also provides utility asset owners with a useful resource that can be incorporated in the procurement of vegetation maintenance services that involve the application of herbicides.

About the Author:
John W. Goodfellow ([email protected]) is a principal consultant for BioCompliance Consulting Inc. and a vegetation management researcher with more than 30 years of experience in the electric utility industry. He has held positions of responsibility for vegetation management, engineering and field services at three large investor-owned electric and gas utilities. He has also managed transmission and distribution services for a major contracting organization. He has bachelor's degrees in forestry and natural resources management from Syracuse University and the SUNY College of Environmental Science and Forestry.

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