THE LEAFLET

Last week in our month-long mythbusting series, we debunked the “trees and crime” myth that perpetuates the idea that trees, bushes, and other vegetation can obstruct views and sightlines that cover criminal activity, thereby encouraging criminals and raising crime rates.

However, we concluded – through a growing body of research – that there is a strong relationship between high tree canopy percentage and lowered crime rates. Indeed, planting trees may reduce crime, in addition to the long list of other benefits trees provide our neighborhoods and greater community.

For the third installment in our mythbusting series, we look at the “trees and utilities” myth. In an urban environment, there are plenty of infrastructure to consider when planting a tree – power lines, water pipes, gas lines, sewers, communications cables, and more. Homeowners may be hesitant to plant a tree on their property because of perceived damage to power lines and underground buried utilities like water pipes and sewers.

At Casey Trees, we believe that our urban forest is as vital to our city as any other public utility we deem essential. Our city’s trees can truly be considered another type of public utility, just as important to our public health, environment, economy, and well-being as our power grid, water supply, and sanitation. It is important to consider our trees when designing our urban landscape, and plan for how trees, power lines, and underground pipes will interact and coexist with one another.

Our Casey Trees arborists take special care when planting trees to give sufficient distance from power lines, and space from underground utilities. Our planting plans incorporate tree species selection and planting practices that ensure the long-term viability of both the tree and surrounding utilities. A tree that is not a good match for the space will likely be insufficiently cared for and inadequately pruned as it matures, so that both the tree and the surrounding structures will be adversely affected.

For several years, Pepco (DC’s power utility) has partnered with Casey Trees to plant trees under or near above-ground power lines in DC. To quote Donna Cooper, Pepco region president, in a press release launching the program years ago, “This program helps to beautify our communities and enhance the environment by providing education and awareness on planting the right tree in the right place. We are pleased to offer a program to our valued customers that extends important aesthetic and environmental benefits, while also promoting safety and service reliability”.

When selecting a tree, it is important to consider the ultimate mature height of the tree. Small trees, those that will grow less than 25 feet tall at maturity, are the only trees that should be considered for under or near power lines. Examples of small trees suitable for the DC area include serviceberry, redbud, sweetbay magnolia, and flowering cherry species. Medium trees that grow to a height of 40 feet or less, such as honey locust, hornbeam, birch, and sweetgum, should be planted further away from power lines. Tall trees such as maple, sycamore, oak, spruce, elm, linden, and pine should be planted well away from wires.

Our above-ground power lines are an evident and visible piece of our infrastructure, but much of our utilities are underground and invisible to us in our day to day lives. Every DC home may have different underground utilities (gas, communications, etc.), but all have water and sewer piping that should be considered when planting a tree.

We recently spoke with Nichol Bell Sowell, Senior Manager in Sewer Operations at DC Water about the interactions between trees and pipes underground. “Trees are good for the environment for a number of different reasons. And sewers have a warm, wet, nutrient rich environment that can attract tree roots”, said Sowell. “So we do observe tree root intrusions in our sewers – as small as what we consider to be ‘fines’, very small roots, to very large root balls that can obstruct the entire diameter of pipe”.

With proper planning and placement, many tree species can be planted around underground utilities like water and sewer pipes.

Sowell reports that most instances of root intrusion occurs in the right-of-way, where street trees or trees on public land are already planted closer to sewer pipes. This is where DC Water has proactive programs (which involves sending a robotic camera down the length of the sewer pipe!) to identify, treat, and further prevent obstructions to main line pipes. Though she advises: “Whether it’s street trees or residents planting trees, it’s just about knowing where the sewer line is located, and not planting in close proximity to those pipes.”

There is no official distance that a tree should or should not be planted from water or sewer lines, as this can depend on several factors, including tree species selection. However, when planting trees, Casey Trees maintains a minimum distance of 3 feet and is careful to incorporate a plan that gives adequate space to ensure that tree roots do not harm pipes or other underground infrastructure. Consequently, this also ensures that the tree has enough soil space for the tree to grow and thrive as it matures.

Before digging or excavating, homeowners should submit a ticket with Miss Utility or call 811 to request service to mark any underground utilities located on their property. The service is free and quick. Miss Utility sends a surveyor within 4 business days of submitting a ticket. Having your property marked before digging ensures safety when excavating and proper planting distance from any underground utilities. Note that when Casey Trees is planting your free tree(s), we take care of this step for you.

At Casey Trees, we adhere to the motto “right tree, right place”. With proper planning, tree species selection, and care, there is a spot for a tree on almost any property or space in DC. Apply today for your free tree planting, which includes a free consultation with one of our arborists to ensure you choose the right tree for the right place!