Delivery of aggregate base material for the project’s construction access drive north of the CSX r/r east of M-6.
Compaction of sand base material for the project’s construction access drive north of the CSX r/r east of M-6.
Excavation and placement of the project’s first manhole structure.
Installation of the first manhole structure’s concrete cover.
Installation of the first section of the project’s 48 inch concrete storm pipe.
Project’s new construction access drive off 48th Street east of the M-6 Expressway.
Construction access drive around the Thornapple Pointe Golf Course maintenance building.
Staked location for boring pit to construct the 48 inch storm pipe under the M-6 Expressway.
Storm pipe construction area within the wooded area east of the M-6 Expressway.
The contractor is constructing the temporary dock to allow the installation of a cofferdam which is necessary for the installation of the storm water diffuser below the river bottom.
The temporary dock is built to handle a crane for continued dock and cofferdam construction.
The contractor continues construction of the cofferdam in the river using sheet piling.
The contractor begins construction of the cofferdam on shore.
Here the contractor is using a heavy vibrating pile driver to set the sheet piling.
Here the contractor is using a crane with a clam bucket to excavate material from inside the cofferdam. This excavation is necessary to set the grade for the future storm pipe.
Scuba divers were necessary to inspect the grade at the bottom of the trench within the cofferdam.
After manufacturing, the High Density Polyethylene Pipe (HDPE) diffuser was delivered to the site in two pieces.
The two pieces of the diffuser are being joined together using a large plastic pipe fusing machine.
Here the contractor is moving a single-piece three hundred and sixty foot section of 48 inch HDPE pipe downhill to connect to the diffuser.
The top end of the three hundred and sixty foot section of HDPE pipe.
The contractor begins lifting and moving the four hundred and thirty foot section of 48 inch diffuser and pipe towards it’s final resting place in the riverbed.
Here two cranes are lifting the diffuser and pipe out over the river cofferdam for installation.
Crane operators and contractors on the ground are communicating adjustments to the pipe alignment.
The pipes alignment with the cofferdam is complete.
The contractor begins lowering the pipe into the cofferdam.
The contractor also used two excavators to assist with the pipes alignment and the lowering of the pipe into the cofferdam.
Here the pipe is being lowered into the water where the pipe will be filled and sunk to the bottom of the trench below the bottom of the river.
The upstream end of the 48 inch HDPE pipe is connected to a manhole structure.
The pipe is connected to a steel flange pipe section at the manhole and forms for a steel bar reinforced concrete collar have been constructed.
Here the contractor is pouring concrete into the collar formwork.
This photo shows the contractor removing the sheet pile cofferdam from on shore and the river.
The 48th section (past section) of 48-inch concrete pipe being jacked into place under the M-6 Expressway.
The bore machine sees the light of day on the east end of the 48-inch storm pipe jack under the M-6 Expressway. The picture shows a bright dot inside the pipe which is the west end of the 400-foot long 48-inch pipe.
Contractors clean the material from the bore machine. Once cleared the machine was pushed forward and removed from the site.
Here the Contractor is placing sand in the receiving pit to which is used as bedding material around the 48-inch pipe.
Here Contractor employees place sand around the 48-inch pipe and prepare it for compaction with portable compactors.
Here the Contractor employees exit the manhole drop structure after finishing work inside the manhole.
Delivery and installation of the 60 inch storm pipe from treatment system east to M-6.
Stripping and stockpiling of topsoil from the detention basin and treatment cell areas.
Excavation of the main detention basin’s northeast corner.
Mass grading and excavation of the treatment cell areas using multiple off-road dump trucks.
Finish grading for the northeast secondary detention basin.
Northeast secondary detention basin after finish grading and seeding.
Placement of clay liner in the treatment cells.
Construction of the first of six siphon chambers which release water from the Stages 1 and 2 treatment cells to the Stage 3 treatment channel.
Interior of the siphon chamber. All six chambers are identical. Each chamber has two siphons, pressure balancing pipe work, a float cycle counter, a flow meter, and vent piping.
Once the clay liner of the treatment cells has been compacted the cells were lined with felt fabric barrier to allow contractors to place the collection piping system.
High Density Polyethylene (HDPE) pipe and HDPE Infiltrators were installed for collection of the water after traveling thru layers of treatment medium.
In the foreground is the final Stage 1 treatment cell under construction. Beyond this cell is one of the Stage 2 treatment cells showing the stormwater distributing piping.
This photo shows the contractor using a long-arm excavator to place the large (2 – 3 inch) stone over the collection pipe system of a Stage 2 treatment cell.
The contractor also utilized a conveyor and smaller light-weight dozer to distribute he large stone medium within the treatment cells.
Here the contractor has just finished the placement of the large stone medium in this Sage 2 treatment cell. Note the pink/red pipes protruding from the stone. These pipes have a dual purpose, they will act as an access point for cameras during inspections and they will also provide an entry point for airflow to the treatment medium below.
The gray box-shaped object is one of 12 structures that will act to control the water level in the treatment cells. Each cell will have one of these control structures. Water levels will be controlled at the downstream end to the collection piping. Along the left side of the photo is a maintenance drive allowing access to these structures.
Here distribution piping has been placed over two layers of treatment medium thru which the stormwater will flow. It is in these layers where the treatment bacteria will live. As the stormwater flows thru this medium the bacteria will break down the glycol into water (H2O) and Carbon Dioxide (CO2).
Here the final layer of pea gravel is being placed over the stormwater distribution pipe network. Note the inspection access pipes have been extended with white PVC and vent caps. Also shown in this photo is the cover layer of compost/peat to be seeded.
Here we see one of six siphon chambers. One can see the large silver vent pipe to allow the structure to breath. The smaller gray canister looking feature is a flow meter. The gray box mounted to the steel posts is a cycle counter. The taller gray box protruding from the stone treatment cell is the water level control structure. The silver metal cover in the foreground is the maintenance access hatch to the siphon chamber.
This photo shows the Stage 2 treatment cells at various levels of construction. Left of the maintenance access drive are the Stage 1 treatment cells under construction.
Here the contractor begins work on the first of six dosing chambers. Stormwater from the detention basin will flow into these chambers. Once the water levels are at the appropriate level the two siphons will drain the water from the chamber forcing (dosing) the water into the Stage 1 treatment cells thru a distribution piping network.
Here contractors are placing rebar and forms to prepare for a single concrete pour of the walls and roof of this underground dosing chamber.
This concrete structure is referred to as the splitter box. The function of this structure is to distribute stormwater flowing from the detention basin to the six dosing chambers. Stormwater flows from one large (24”) pipe into this chamber and flows out three smaller (12”) pipes to pairs of dosing chambers. The structure is equipped with an adjustable water level device to allow for the appropriate flow into the three outgoing pipes.
All Stage 1 treatment cells have been equipped with comprehensive aeration piping systems for future treatment capacity. These systems include four large diameter (3-4”) manifolds and hundreds of small perforated tubs. In the future when needed the perforations in these small tubes will allow pressurized air to be pumped into the stone medium increasing the cells treatment capacity.
Here aeration piping is being placed and stone medium is being spread over the tubing. Several layers of different types of medium will be placed before the distribution piping is installed.
Stage treatment occurs within this stone line drainage ditch. Water will be siphoned out of the Stage 2 treatment cells into this ditch for final treatment. Whatever glycol remains in the stormwater will flow through this ditch for final treatment.
Here one can see the Stage 1 treatment cells have been covered with the final mulch layer placed over the stone medium. This area will be seeded and maintained as low growing grass. One can also see the white video access and ventilation piping.
These two overflow structures were constructed to allow for high stormwater flow circumstances. These circumstances occur as rain storms in the fall and spring when little or no deicing activity typically takes place. The initial/first flush flows will go through treatment after which the higher flows will go through these structures into the Stage 3 treatment ditch. Again, remember little to no deicing typically occurs during these types of rain events. Thus the need for treatment is minimal to none.
All stormwater from the airfield will come through this outfall structure into the main detention basin. Here the formwork has been removed. Backfilling and installation of the stone rip-rap has yet to occur. Note, one can see the 9 foot storm pipe on the left side of the structure.
The outfall structure receives the stone rip-rap for erosion protections.
A steel grate is placed over the 9 foot outfall. Note the round catch basin grate to the right. This grate is removable to allow access to a sumo which will trap sediment from the stormwater. All low flows will travel through this structure and enter a 12 inch pipe to a trash filtration structure located on the east side of the main detention basin prior to entering the treatment system.
Here we see the trash filtration structure at the east end of the main detention basin. Pre-filtration is accomplished with grass and stone rip-rap structures in the detention basin. The trash filtration structure utilizes various sizes of filter grates.
Here one can see the trash filtration grates on the trash filtration structure. The outside or coarse screen grate has a bar spacing of 1-3/16 inches. The inside fine screen grate has a bar spacing of 9/16 of an inch. The purpose of this structure is to keep all stray materials from entering the treatment system and provide a place where maintenance staff can collect and dispose of the debris properly.
Here the contractor is placing the 9 foot storm pipe from the main detention basin to a location where the pipe will go under 36th Street.
Here you can see additional 9 foot pipe waiting to be installed. Currently most of the 9 foot pipe in the direction of the 36th Street crossing has been installed.