Municipal Hydrogeological and Regulatory Consulting Services – City of Westminster, Carroll County, MD

The City of Westminster is a fast-growing bedroom community within the Baltimore metropolitan area, which historically has relied on surface water for municipal supply purposes. Westminster maintains an off-line pump-storage reservoir. Similarly, to Frederick and other municipalities, the surface water resources of the Westminster area have conjunctive uses for potable supply and for the assimilation of treated wastewater effluent. Those surface water resources that are not used consumptively continue downstream and augment the supply available to Baltimore City at Liberty Reservoir.

In 1980, the cities of Westminster and Baltimore entered into a consent order brokered by an MDE predecessor agency, which established sub-allocations and flow-by restrictions that since have governed the effective safe yield of the regional surface water drainage basin. When Westminster contemplated drilling a reservoir augmentation well in the late 1990s, ALWI hydrogeologists forecast the availability and allocability of groundwater resources and assumed responsibility for critical negotiations with several MDE agencies. We came to recommend against the project, because of allocability limitations and well construction challenges.

Also during the 1980s, Westminster developed a high-capacity satellite wellfield in the karst limestone of the Wakefield Valley. Changes in MDE water appropriation policy combined with the early 1990s development of an upgradient golf course caused the downward adjustment of Westminster’s groundwater allocation. Our hydrogeological staff assisted in studying well interference issues, assessing karst groundwater flows and recharge issues, and otherwise developing a technical database supportive of the highest feasible allocation in the face of changing MDE appropriation policy. One outgrowth of the revised Wakefield Valley permits involved our work in deploying and maintaining low-flow measurement equipment for the purpose of better quantifying drought-level groundwater recharge rates.

With the allocation to the municipal wells in the Wakefield Valley curtailed semi-permanently based on the limited allocable footprint of the water service area, the City and ALWI turned attention to the development of additional groundwater supply capacity elsewhere in Town. Work began earlier in the 1990s in the development of a series of stand-alone municipal production wells, in both carbonate and non-carbonate aquifers. ALWI’s hydrogeological staff continues to provide the following professional services in support of the development of three additional municipal supply wells over past ten years:

  • Feasibility studies, focused on quantifying annualized allocability and drought-of-record availability;
  • Well siting, using fracture trace analysis, geologic fabric analysis and geophysical VLF and terrain conductivity methods;
  • Regulatory coordination, including filing permit applications and coordinating for well site approvals;
  • Drilling program design, bid specification development; solicitation of drilling proposals, coordination of fieldwork in drilling and testing wells;
  • Technical and scientific control of field data collection, including quantitative and qualitative measurements of changes in yield, drawdown, potentiometric head and water quality in response to drilling and testing;
  • Aquifer testing design, execution and interpretation, including turnkey address of off-site monitoring requirements and adverse impact issues as they arose;
  • Data reduction, interpretation; safe yield assessments; computer modeling of bedrock hydrogeological systems for accurate and defensible prediction of drawdown effects; fulfillment of local and state permitting requirements;
  • Completion of administrative permitting requirements; regulatory liaison through review and public advertisement processes; expert testimony at public informational hearings.
  • Negotiation of permit conditions favorable to the City; ongoing liaison with regulatory agencies post-permitting.

During the course of the development of these other groundwater supply wells, other technical issues arose from time to time. ALWI’s hydrogeological staff assisted City personnel in performing other tests and evaluations focused on maximizing the safety and quantity of the available supplies.

For example, in the late 1990s, City Well No. 4 was found to contain trace concentrations of ethylene dibromide (EDB), a Rule V Volatile Organic Compound (VOC) used as an aviation fuel additive and agricultural fumigant. ALWI’s hydrogeological staff assessed the relationship between flow rate, flow duration, pumping water level and EDB concentration. Absent a consistent trend that could have suggested an operations-based solution, the City retrofitted the treatment system with carbon filtration.

During the drought of 2002, ALWI assisted the City in securing regulatory approval for the use of the Lafarge Medford Quarry as an emergency water source. The Quarry is located in karst terrain and potentially down gradient of the discharge point of the wastewater treatment plant effluent. To address MDE concerns about possible wastewater recirculation into the quarry via conduit flow in the karst terrain, ALWI designed and executed a quantitative dye tracing study to measure the degree of quarry discharge that came from the wastewater plant. ALWI also provided technical assistance to the City in obtaining a water appropriation permit for the use of the quarry on an occasional and as-needed recurring basis. The work was highly successful, and MDE approved the use of the quarry as a supplemental water source for use during periodically recurring drought crises.

In 2003, ALWI was requested to provide technical advice and professional oversight of work to investigate and remediate a large sinkhole that opened in a residential neighborhood of downtown Westminster on July 27, 2003. The sinkhole, and our professional opinions regarding it, has been covered extensively in the media.

ALWI has completed a draft of a comprehensive citywide Source Water Assessment and Wellhead Protection Program. We characterized the hydrogeologic framework surrounding and upgradient of 11 City wells. We delineated the probable surficial and subsurface capture zones contributing recharge to the wells. We identified several point source and non-point contamination hazards. We developed wellfield management and risk mitigation strategies to protect against future adverse impacts to water quantity and quality. Please read our news story about this important project, or read the article in the Carroll County Times. A workshop meeting, wherein the work will be discussed publicly, has been scheduled for April 21, 2005 at 7 PM at the Westminster Volunteer Fire Department. The draft report and its major attachments can be reviewed at

http://www.westgov.com/planning/swap.asp

Email Newsletter icon, E-mail Newsletter icon, Email List icon,  E-mail List icon Sign up for our Email Newsletter
email list
For Email Newsletters you can trust