HARSB removes residential and non-residential pollution EVERY DAY !!
-- On the Average, each person in the U.S. contributes 50-100 gallons of wastewater each day.

If we don't remove pollution the river and aquifer become polluted and quality of life in the valley
would decrease. 
-- A Wastewater Treatment plant removed solids: This includes everything from rags, sticks, rocks, sand, etc. found in wastewater
-- A Wastewater Treatment plant reduces organic matter and pollutants: Helpful bacteria and other microorganisms are used to consume organic
    matter in wastewater.  The bacteria and microorganisms are then separated from the water
-- A Wastewater Treatment plant restore oxygen:  Treatment facilities help ensure that the water put back into our lakes or rivers has enough
    oxygen to support life.

Note: While our lakes and streams clean water in much the same way, wastewater treatment plants are faster and can handle more water.  This makes
treatment plants essential in areas where there's too much wastewater for nature to handle alone.

Let Us Start a Basic Tour of the HARSB Facility:


The headwork's receives influent from the City of Hayden, Hayden Lake Recreational Water and Sewer District, and Kootenai County Airport.

headworks picture

Inside the Headworks  is the Step Screen and Grit System.



The Step Screen removes materials that should not be in the system.  The material that is removed is sent to the Landfill.
Sewer users should put all materials except toilet paper in the trash, this would reduce maintenance issues and costs.

The Grit System:  The Grit Seperator has a series of trays that work like a "mall penny parabolic game".  Water flows in the side and spins
around.  Sand, stones, and grit settles to the bottom.  Water and Organics flow on to the plant.  The Grit pump removes the material
from the bottom of the Grit Seperator and sends it to the Slurry cup which washes the organics out of the grit and then sends the organics back
into the plant.  The Grit dewatering screw dries the grit before discharge into the dumpster to go to the landfill. 

Equalization Tank and Biological Nutrient Flow Control

eqeq pump station 

The Flow Control Valve is set for a daily flow rate and is measured by a flow meter.  The set flow rate is at 1 million gallons per day to the biological process.
Excess flows above 1 million gallons per day in the morning flows into the equalization tank.  In the afternoon and the middle of the night when water flow rates
drop below 1 million gallons per day, water is pumped from the equalization tank to maintain the constant flow and organic load to the biological process.

Anaerobic Tanks and Anoxic Tanks

anaerobic and anoxic tanks

Anaerobic tanks have ZERO "No" dissolved oxygen.  The Bacteria "Bugs" desperate for oxygen break down the Phosphate (PO4) releasing the phosphorus and
consuming the oxygen to stay alive.  Time in Anaerobic tanks is about 2 hours.  Mixers move the water so bugs can find Phosphates to break down.

Anoxic tanks have near zero dissolved oxygen.  But bacteria must breakdown the nitrate molecule (N03) to consume the oxygen (02) and release
nitrogen (N2) to the atmosphere with the other 78% nitrogen in the air.  Mixers move the water so bugs can find nitrates.

Oxidation Ditches



Surface aerators provide high oxygen aerobic conditions.  Bacteria eat organics, consuming oxygen (02), and make more bacteria (solids) "Eating and Reproducing"
Bacteria converts ammonia- 1 nitrogen and 3 hydrogen atoms (NH3) to nitrate- 1 nitrogen and 3 oxygen atoms (N03).
Bacteria take up the phosphorous they released in the anaerobic tanks plus extra phosphorous (like a squirrel packs nuts in their cheeks).  Phosphorous (P) is converted to
phosphate (PO4).  Bacteria, Bugs, and Solids, overflow the oxidation ditch to the clarifiers.



This clarifier is a quiet place for microogranisms and solids to form clumps and settle.  It has a mechanism that collects the solids so they can be returned/recycled back to the Anaerobic tank to start the process over.
The clean water overflows and goes on to disinfection.  We are able to remove part or all the solids (wasting), to control the population of bugs, to the waste sludge holding tank.

Waste Sludge Holding Tank

 The solids are removed from the Clarifier and placed in the holding tank.  Air is pumped into the tank to maintain high dissolved oxygen condition to keep the solids
fresh and easier to dewater.

Chlorine Disinfection

chlorine bldgchlorine gas

Chlorine gas is added to water to make a strong chlorine solution.   Chlorine kills disease causing organisms.  Water is then recycled to the Spokane River during winter months
or to the Reuse Farm during the growing season.
Fact: "Chlorine Disinfection is credited for the large increase in world population growth in the 20th Century because it kills disease causing organisms."

Screw Press (DeWatering)

 Polymer is added to make the solids stick together and release water.  The press squeezes the water from the solids making dryer biosolids (cake).  Biosolids meet EPA
requirements so they can be recycled to the farm as an organic soil conditioner and fertilizer to make crops grow better.




On site testing to control the biological process and monitor the water to insure it meets water quality requirements.