CASE STUDY

Lynchburg, VA

Meeting MS4 and Chesapeake Bay Program Compliance While Achieving 90% Savings on Phosphorus Reduction

The Challenge

Located in the foothills of the Blue Ridge Mountains, Lynchburgsits along the historic James River, Virginia’s largest source ofdrinking water supply for 2.7 million people. The river also drainsinto the Chesapeake Bay, making the City of Lynchburg subjectto special conditions for its MS4 system. Upstream fromRichmond and at the center of Virginia’s fifth largest metro area,the City needed a new approach to meet its TMDL permit whileprotecting both water bodies from stormwater pollution.

The Solution

To help meet its MS4 permit and Chesapeake Bay TMDL ActionPlan goals, the City of Lynchburg used Opti’s ContinuousMonitoring and Adaptive Control (CMAC) with an existing regionaldetention facility, Warren Pond. CMAC integrates data directlyfrom field deployed sensors with real-time weather forecast datato monitor performance and make automated and predictivecontrol decisions to actively manage stormwater storage andflows across the watershed.

This approach helps Lynchburg achieve its goals by increasingrunoff residency time, mitigating peak flows, and generatingwater quality credits to help the City achieve 100% of its annualnutrient reduction targets.

At a Glance

$1,852/lb Phosphorus reduced
Operating since 2017
Offsetting CAPEX with anexisting BMP

“Retrofitting this facilityusing CMAC has provento be a cost-effectivemeasure to improve thefunction of an existingstormwater pond andmeet reductionrequirements.”

City of Lynchburg
Dept of Water Resources,
Chesapeake Bay TMDL
Action Plan
Prepared by Greeley & Hansen

ECONOMICAL
CAPEX
90% Savings
on Phosphorus Reduction
‍
RESILIENTPeak Flow
43% Reduction

PEACE OF MINDReal-Time Monitoring
for Proactive O&M

The City of Lynchburg was the first to model retrofitting an existing dry pond with CMAC to function like a wet extended retentionpond for generating water quality credits using the Chesapeake Bay Retrofit Curve Model.

Results

Since 2017, Opti’s CMAC controls over 158,000 CFby utilizing the dry pond’s available capacity. Byretrofitting Warren Pond with Opti’s CMAC, the Cityof Lynchburg achieves 5% of its pollution reduction goals for Chesapeake Bay TMDL and 100% of itslocal TMDL goals to meet its MS4 permit. Benefitsinclude:

Increased water quality and flood mitigation
Improved nutrient load reduction to meet permits
Centralized and secure dashboard for real-time,data-driven O&M
Ability to automatically control and reduce wetweather discharge from the pond storage facility

Source: Warren Pond POC (Pollutant of Concern) TMDLreduction credit approved on July 15, 2021, as reported inthe City of Lynchburg MS4 Program Plan for 2018−2023

CMAC is approved byCBP’s Urban StormwaterWorkgroup and carriesreciprocity in 6 states andthe District of Columbia.

About OptiRTC

Opti, an Aliaxis company, is the leading provider of digital adaptive stormwater control solutions.With over 300 deployments to date, Opti empowers customers and partners to address theimpacts of climate change, aging infrastructure, urbanization, and water pollution, enabling themto secure the sustainability of our communities and natural resources Opti’s cloud-basedplatform optimizes stormwater asset performance through instant actionable insights to provideeconomic savings, resilient solutions, and peace of mind. With our commitment to innovation, weare driving a resilient and brighter future for all.