Mastering the municipal reuse master planning process

This article has been adapted from “Addressing Water Supply Gaps with Reuse: Tailoring a Reuse Master Plan for Your Needs,” a recent webinar from CDM Smith featuring the expertise of Jillian Tedder, P.E. and Johnathon Sheets, PhD, PE.. Stream the full webinar here and earn a PDH for attending.

When it comes to reuse master planning, every entity has different needs and therefore projects will range in size and scope. To help find the right plan for you, we have broken down the process into a few steps.

Under­stand­ing growth

The growth assessment is often part of broader planning efforts. It typically begins with population projections for a chosen planning horizon. Next, we examine the development pipeline, encom­pass­ing residential, commercial, and industrial sectors. For instance, we may consider the impact of tech companies entering a given area and evaluate their water demands and wastewater generation.

Evaluating Large Water Users

The methodology for evaluating large water users varies depending on the utility. In general, we utilize water billing data to determine the amount used for non-potable appli­ca­tions. Subse­quently, we spatially map these users and group them into geographic areas that assist in identifying low-hanging fruit project oppor­tu­ni­ties. This analysis considers both current and future usage.

Evaluating Infra­struc­ture, Capacity and Water Quality

The next step is to evaluate infra­struc­ture, capacity, and water quality. Oftentimes, condi­tion ­times, condition assessments on existing infra­struc­ture are performed. The conveyance coverage of the distri­b­u­tion pipe network is mapped such that potential future conveyance options for reuse can be explored. 

From a quantity standpoint, it’s crucial to consider reclaimed water avail­abil­ity. This avail­abil­ity depends on return flow require­ments and any existing contracts related to non-potable reuse allocations.

Regarding water quality, we first delve into available historical data. Our analysis aims to determine whether the system can meet existing or projected regulatory standards for wastewater discharges and non-potable and/or potable reuse water regulations and guidance, which are state-specific. In many cases, there are supple­men­tal sampling needs for critical source water evaluations which focus on both regulated and unregulated compounds.

Assess Existing Reclaimed Water Systems

When evaluating existing reclaimed water systems, the capacity for expansion in terms of size and proximity to potential anchor users is explored in more detail. 

Define Regulatory Pathway

Defining the regulatory pathway is an effort that is often under­es­ti­mated, but the time commitment, cost, and effort required are not insignif­i­cant. The regulatory landscape varies signif­i­cantly by state and application. Many states are adopting official direct potable reuse regulations, such as Colorado and California. it is crucial to consider the timeline required to develop a permit application and obtain approval for the project. This time frame should be factored into the overall imple­men­ta­tion timelines for each of the project alter­na­tives.

Form Projects and Develop Planning Level Costs

Finally, we collab­o­ra­tively develop project alter­na­tives with our clients, which typically also involves visual repre­sen­ta­tions of each alternative in terms of new infra­struc­ture, conveyance, storage, wastewater treatment plant improve­ments, and water treatment plant enhance­ments such as advanced treatment processes.  Next, we qual­i­ta­tively assess the benefits and potential risks associated with each option.

Planning level costs development incor­po­rates capital and operational and maintenance (O&M) costs. We cost capital improve­ments such as plant upgrades, advanced treatment, conveyance, storage, pump stations and site improve­ments. Addi­tion­ally, we account for supple­men­tal costs that should not be overlooked, such as source water char­ac­ter­i­za­tion, piloting, permitting, and public outreach programs critical in the success of non-potable and potable reuse projects. 

These project alter­na­tives and planning-level costs are often integrated into another multi-criteria decision-making process such as an IWRP or One Water Plan. Decision-making processes typically outline metrics and performance criteria for each option, aiding utilities or corpo­ra­tions in prior­i­tiz­ing projects from the present into the future.