City and Borough of Juneau
Wastewater Utility Division
Juneau's first wasetwater treatment facility was a 0.02 million gallons per day (mgd) secondary package plant, installed on City and Borough of Juneau (CBJ) property at 2009 Radcliffe Road in the mid 1960s. This facility was built by the developer of the Airport Shopping Mall (the old IGA Grocery Store) to service their wastewater discharge requirements.
The Mendenhall Valley was growing with the development of housing and business at this time. This development caused numerous septic tank problems with the high water table that is predominant throughout the Mendenhall Valley. CBJ took action to correct the health problem that septic tanks were causing by building a 0.5 mgd package plant and installing a wastewater collection system in the most populated area of the valley. This secondary extended aeration treatment facility began operation in 1972.
From 1972 to 1976, the Valley continued to develop resulting in the original 0.5 mgd treatment facility more flow than its design capacity. By 1976 the facility was bypassing 0.5 mgd or more each day.
Enlargement of the 0.5 mgd facility was completed in 1978. The expansion added two new clarifiers, an Aerated Bio-Filter (ABF) tower and additional aeration. This brought the treatment to 1.42 mgd average flow, with short peak flow to 3.1 mgd.
The new ABF Treatment Facility had no waste sludge process capability. Up to this time, all waste sludge was hauled by tanker truck and dumped into the the Juneau-Douglas Treatment Facility sludge holding ponds. In 1979, a belt filter press was installed at the ABF Treatment Facility and a six-acre waste sludge disposal landfill was completed and became operational.
Continued growth in the Mendenhall and Lemon Creek Valleys required new wastewater collection systems. Ten new pumping stations and associated interceptor sewers were added to carry wastewater to the ABF Facility. Development continued and 1982, the ABF Facility was treating 2.0 mgd daily and was again over design capacity during wet weather peak flow periods with influent flows of 4.0+ mgd. Correction of inflow and infiltration (I and I) in the collection system began. However, an expansion of treatment capacity was required by the Environmental Protection Agency (EPA) to reduce the numerous discharge permit violations.
The ABF Treatment Facility was built on property that had limited room for expansion. Because of the limited area, most treatment methods could not be utilized for the required expansion. The SBR treatment method was utilized for the small available property and qualified for 85 percent funding from the EPA. Construction of the SBR Facility began in 1986. In 1989, half of the new SBR Facility was operational and started treating wastewater.
Between 1989 and 1991, modifications were made in various control equipment and process control strategies that have resulted in BOD and suspended solids removal rates improving to the mid-90% range in addition to increasing daily average flow capacity. The ABF Treatment Facility capacity is 1.42 mgd. The SBR Treatment Facility capacity is 4.9 mgd with peak flows up to 7.81 mgd. The two facilities can treat a combined peak flow of 9.23 mgd. Plant treatment capability is projected for wastewater flows anticipated through the year 2006.