Tazewell County PSA Claypool Hill WWTP

The Tazewell County PSA engaged T&L in March 2012 to update the Preliminary Engineering Report (PER) to address a stringent VPDES limit for ammonia which was imposed on the TCPSA by the Department of Environmental Quality (DEQ). The PER recommended an upgrade and expansion of the existing WWTP from 0.35 MGD to 0.75 MGD capacity address the stringent ammonia discharge limit and meet the future needs of the Claypool Hill and Wardell service areas.

Project Funding: T&L provided assistance to the TCPSA in securing the project funding with included multiple funding agencies, each with differing requirements. Funding agencies included:

DEQ/RLF (LOAN) $8,255,550
DEQ/RLF (GRANT) $1,000,000
SWVA W/WW $400,000
LOCAL $252,520
TOTAL $9,908,070

In July 2012, T&L began final design phase services for the upgrade and expansion of the WWTP. Construction was completed in October 2015 at a cost of $5.7 million, which was approximately $1.0 Million under T&L’s engineering estimate of $6.7 Million and 1.6% above the award amount. One important step taken by T&L, which was a big factor in the success of the project, was the use of a pre-qualification process prior to the formal bidding process. This provided the TCPSA with reasonable assurance of a pool of bidders with the experience and capacity to undertake a specialized wastewater treatment plant.

The entire project was completed $1,535,019.21 under the TCPSA’s budget.

Claypool Hill WWTP I&I Study

T&L performed an analysis of sanitary sewer flows in support of the Tazewell County Public Service Authorityís Claypool Hill Wastewater Treatment Facility upgrade and expansion project. The analysis was performed to determine whether or not excessive inflow and infiltration was present in the collection system in order to satisfy Virginia Clean Water Revolving Loan Fund requirements.

Wastewater treatment plant influent flow records were utilized to convert flows seen at the wastewater plant to a per capita basis based on the total equivalent population of plantís service area. The conversion of the flow to a total equivalent population basis of gallons per capita per day was important to account for the relatively large contribution of commercial users in the service area.

Running seven day flow averages, as well as flow data from each day over an eleven month period, were compared to precipitation records and water use records to examine for any potentially excessive inflow and infiltration as defined in the Virginia Clean Water Revolving Loan Fund guidelines, Section 8. Although there were a few periods which would be defined as having excessive flow days, T&L was able to demonstrate that these problematic flows were corrected by the efforts of the Tazewell County Public Service Authority. T&L was able to demonstrate to the satisfaction of DEQ that excessive inflow and infiltration was not present in the sanitary sewer collection system.

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