Exhibit 4 - PresentationEffluent Filter, Aeration Diffuser, and
Digester Improvements PCWRP
DENTON CITY COUNCIL -22-520 –MARCH 22, 2022 1
Outline –Phase 1A
•Age and Condition
•Current Flows
•Anticipated flows
•Texas Commission on Environmental Quality
(TCEQ)Requirements
•Phase 1 Improvements:
•Filter Rehabilitation
•Aeration Defuses
•Anaerobic Digester
•Selection process
2DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
City of Denton Pecan Creek Water
Reclamation Plant Current Conditions
•The existing wastewater treatment plant is an almost 60 yr
old facility
•Key components of the plant have reached the end of the
useful life.
•Processes are proposed to be upgraded for additional
capacity using newer technologies.
•Current effluent filtration process uses sand media, an
inefficient process.
•The existing Aeration Diffusers are 20 plus years old and have
become inefficient and problematic.
•The Anaerobic digester lid is over 40 yrs. old and has reached
the end of its functional life.
3DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
City of Denton Pecan Creek Water
Reclamation Plant Current Conditions
•Pecan Creek Water Reclamation Plant:
•Permitted for 21 MGD Annual Average Flow and 46 MGD
Peak Flow.
•Flows are at 71% of permitted average daily flows.
•The Texas Commission on Environmental Quality (TCEQ)
require when 75% of the permitted flows are reached
capacity upgrades must be in design.
•When 90% of the permitted flows are reached, construction
of the facility upgrades and or expansion must be initiated.
4DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
5
Sand Filter
Rehabilitation
•Current filters rated capacity of
20 MGD
•Sand Filters to be replaced with
modern cloth filter, improving
capacity, with no modifications to
the existing footprint.
•Upgrade will increase filtration
capacity to 46 MGD with one
filter out of service (for
redundancy).
DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
Aeration Diffuser Installation
•A new Membrane Diffuser system will be
installed in the existing Aeration Basins.
Replacing the 20 + yr old system.
•These new diffusers resist fouling, they are less
expensive to manufacture and install.
•The membrane diffusers have a longer lifespan.
•The operation and maintenance costs are
greatly reduced.
6DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
Anaerobic Digester
Improvements
•Existing anaerobic digesters will be cleaned.
•A new primary gas holder digester lid will be constructed on
site and installed.
•The new gas holding type lid allows for storage and reclaims
the methane. The reclaimed gas will be utilized to heat the
digester.
•Any excess methane gas will be piped over into a landfill
project in collaboration with Atmos Gas.
7DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
Competitive Sealed
Proposal
•Through the Procurement evaluation
process for this Competitive Seal
Proposal contract firm elected:
•Archer Western Construction, LLC
•$13,509,221 with a contract total
•395 days for construction
Staff recommends awarding Effluent Filter,
Aeration Diffuser, and Digester Improvements
PCWRP contract to Archer Western Construction,
LLC
8DENTON CITY COUNCIL -22-520 –MARCH 22, 2022
Questions?
9DENTON CITY COUNCIL -22-520 –MARCH 22, 2022