City of Dickinson, ND

Waste Water

The City of Dickinson has a Class III Waste water Treatment Plant. The city discharges it’s waste water to the Heart River, which is a class 1A stream. The city’s treatment process consists of Pretreatment, Advanced Aeration and a four cell lagoon system.

For years wastewater lagoon systems have provided secondary treatment performance to many small to medium sized communities. The attributes of these processes have been attractive as cost effective options for the treatment of municipal wastewater. The aeration segment in these systems is the most critical component and is the core of their biological treatment process. A lagoon systems ability to aerate the incoming sewage has a direct impact on the level of wastewater treatment it achieves.

An ample oxygen supply in a wastewater pond system is the key to rapid and effective wastewater treatment. Oxygen is needed by the bacteria to allow their respiration reactions to proceed rapidly. The oxygen is combined by the bacteria with carbon to form carbon dioxide. Without sufficient oxygen being present, bacteria are not able to quickly biodegrade the incoming organic matter. In the absence of dissolved oxygen, degradation must occur under septic conditions which are slow, odorous and yield incomplete conversions of pollutants. Under septic conditions, some of the carbon will be react with hydrogen and sulfur to form sulfuric acid and methane. Other carbon will be converted to organic acids that create low pH conditions in the ponds and make the water more difficult to treat. For example, treated ponds designed to biodegrade wastewater pollutants without oxygen often must hold the incoming sewage for six months or longer to achieve acceptable levels of pollution removal.

Manager: Waste Water Manager