ERU Impervious Area Calculations Rationale

GENERAL

The below scenarios are given to provide general guidelines on how hard surface Areas were evaluated. Most hard surface Areas were measured on City of Plymouth ortho photography at a scale of 1:600 utilizing ESRI Geographical Information System Software. A 95% reduction was taken in the measured Areas to provide a factor of safety in making the measurements. Building permits, drainage plan applications and site plans were utilized to provide the Areas on newer facilities not on the ortho photogaphy. If plan measurements were utilized a 95% reduction was applied. If applications and permits were utilized a reduction was not applied since the information was supplied by the owner or an owner's representative.

All entities that have different facility locations will be billed for each facility location.

Hard surface Areas include roofs, driveways and parking Areas (asphalt, concrete, gravel, stone, etc), impervious coverings (material stacks, multiple vehicles, tarpaulins, etc), and similar items were all measured.

Apartments

PARCELS: Single
SERVICES: Single for a complex
CALCULATION: The total hard surface is measured and one bill will be issued for the entire parcel complex based on that amount.
   
PARCELS: Single or multiple (contiguous) single owner
SERVICES: Each unit has its own service
CALCULATION: Each unit will be charged as a residence; one ERU.
   
PARCELS: Multiple (contiguous) individual buildings are built within parcel constraints single owner
SERVICES: Multiple one for each building or group of buildings on that parcel
CALCULATION: The total hard surface is measured for each parcel and one bill will be issued for each parcel based on that amount.
   
PARCELS: Multiple (contiguous) individual buildings may or may not be built within parcel constraints single owner
SERVICES: Single entire complex
CALCULATION: The total hard surface is measured for the multiple parcel complex and one bill will be issued for the complex based on that amount.
   
PARCELS: Multiple (contiguous) individual buildings are not built within parcel constraints - single owner
SERVICES: Multiple one for each building or group of buildings on that parcel
CALCULATION: The total hard surface is measured for each building (either on parcel or straddling a parcel line) and the parking on the parcel and one bill will be issued for each parcel based on that amount.

If there are two buildings having services on one parcel; one would receive the bill and the other building would not receive a bill.

 

Commercial

PARCELS: Single
SERVICES: Single
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount.
   
PARCELS: Single or multiple (contiguous) single owner
SERVICES: Multiple billed to one customer
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount.
   
PARCELS: Single or multiple (contiguous) single owner
SERVICES: Multiple billed to different customers
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount normally to the property owner.
   
PARCELS: Multiple (contiguous) individual buildings may or may not be built within parcel constraints single owner
SERVICES: Single entire complex
CALCULATION: The total hard surface is measured for the multiple parcel complex and one bill will be issued for the complex based on that amount.

 

Industrial

PARCELS: Single
SERVICES: Single
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount.
   
PARCELS: Single or multiple (contiguous) single owner
SERVICES: Multiple billed to one customer
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount.
   
PARCELS: Single or multiple (contiguous) single owner
SERVICES: Multiple billed to different customers
CALCULATION: The total hard surface is measured and one bill will be issued for the parcel based on that amount normally to the property owner.
   
PARCELS: Multiple (contiguous) individual buildings may or may not be built within parcel constraints single owner
SERVICES: Single entire complex
CALCULATION: The total hard surface is measured for the multiple parcel complex and one bill will be issued for the complex based on that amount.

 

Manufactured Home Parks

PARCELS: One
SERVICES: One master meter
CALCULATION: The total hard surface is measured and one bill will be issued for the entire park based on that amount.
   
PARCELS: One
SERVICES: No master meter; each unit has its own service
CALCULATION: Each unit will be charged as a residence; one ERU.