Four Categories Showing Qualitative Requirements
Category of Facility | Count of Facilities in State (#) | Status | Capital Requirements | O&M Requirements |
1 | 3 | Currently in compliance with 0.5 fps standard; smaller intake (<12 MGD DIF) | Not needed | O&M is assumed to be ½ of EPA’s average O&M estimates because these are smaller facilities. |
2 | 9 | Currently in compliance with 0.5 fps standard; larger intake (>12 MGD DIF) | Not needed | O&M is assumed to be at EPA average O&M estimates because these facilities have a larger intake relative to smaller facilities. |
3 | 14 | Not in compliance with 0.5 fps standard; smaller intake (<125 MGD AIF) or compliance is expected to have low costs. | Less expensive technology required: Examples include passive screens or fish return. | O&M is assumed to be at EPA’s average O&M estimates. |
4 | 2 | Not in compliance with 0.5 fps standard; larger intake (>125 MGD AIF) or expected to have high costs | More expensive technology required: Most likely technology to be used will be a closed cycle recirculating system (cooling tower), where offshore intakes do not already exist. | O&M is assumed to be at EPA’s average O&M estimates. |
As noted above, capital costs will typically be annualized. The main result of this is that the maximum costs in a two-year period will probably occur in the long term when all facilities have received permits and have started both payment of debt and O&M cost per year.
Maximum Total Annual Costs per Year in any = Long Term Annual Costs per Year
Two Year Window for All Permittees for All Permittees
To estimate annual capital cost and O&M cost per year, the department estimated costs for each category. Capital costs were annualized based on 20 years and 5% discount rate. Note that EPA in various rule development documents refers to useful life of 10 to 30 years (the department used 20 years as an average useful life).
Annualized Capital Cost Factor (20 years at 5% discount rate) = 0.08
O&M COST PER YEAR
The department used estimates for O&M cost per year that EPA prepared for the rule (see References below).
The maximum cost a facility is estimated to incur for its monitoring, record keeping, and reporting activities is approximately $84,361/facility/year to $99,900/facility/year in 2002 dollars ($119,902 to $141,988 in 2019 dollars) for Freshwater River/Stream, Lake, and Great Lake.
Using the mean of the range or $131,000/facility/year for all of the categories except category 1: for category 1, the department assumed costs would be one half of EPA’s estimate because costs are expected to be smaller for less complicated compliance options.
O&M cost per year (2019 dollars) = $131,000/facility/year for all groups except category 1
O&M cost per year (2019 dollars) = $65,500/facility/year for category 1
ANNUAL CAPITAL COST
The department considered submerged passive screen intakes and traveling screens with fish return as two examples of less expensive technology and considered recirculating systems as a more expensive technology.
Less expensive technology
The department used estimates for Submerged Passive Screen Intakes and Traveling Screens with Fish Return that EPA prepared for the rule (see References below).
For this section the department used the average design intake flow of Category 3 facilities. This flow was 90 MGD.
Example of installed fine and very fine mesh t-screen system at existing shoreline based intakes:
Using the EPA’s capital cost estimates, the cost range for submerged passive screen intakes, the department estimated $880,339/facility to $5,971,492 in 2002 dollars ($1,254,225/facility to $8,487,274/facility in 2019 dollars) for freshwater installations at locations 20 meters offshore to 500 meters offshore.
Example of capital cost of traveling screen with fish return:
The capital cost of traveling screen equipment is highly dependent on the size and surface area of the screens employed. Given the water depth, intake flow, and through screen velocity, the aggregate width of the intake screens can be estimated using the following equation:
Screen Width (Ft) =
Design Flow (cfs) / (Screen Velocity (fps) x Water Depth (Ft) x Open Area (decimal %))
For a mesh size of 3/8 inch, the corresponding percent open area for a square mesh screen using 14-gauge wire is 68%.
EPA reported that the median value of the ratio of the water depth to the screen well depth for all facilities that reported was 0.66. Thus, based on median reported values, the screen well depth can be estimated by assuming it is 1.5 times the water depth where only water depth is reported. For the previous rule for those facilities that reported water depth data, the median water depth at the intake was 18.0 ft.
For this estimate DNR assumed the medium water depth of 18 feet and intake flow of 90 MGD (139.3 cubic feet per second) to calculate screen width of 22.5 feet at the standard of 0.5 fps.
22.5 = 139.3/(0.5 x 18 x 0.68)
The well depth is then 27 feet.
27 = 18 x 1.5
For adding fine mesh with fish handling and return freshwater environments EPA shows costs as $436,224/facility to $661,024/facility per facility in 2002 dollars ($620,005/facility to $939,513/facility in 2019 dollars) for total width of 20 feet and range of well depth from 25 to 50 feet. The department used the estimate based on a screen with width of 30 feet.
In conclusion, the department estimates a capital cost per facility for scenarios where a less expensive technology is required is in the range of $620,005/facility to $8,487,274/facility (2019 dollars).
The mean of the range is $4,553,640/facility (2019 dollars)
The department used the mean of the range as an estimate of capital cost per facility for scenarios where a less expensive technology is required.
The department estimated the average capital cost for scenarios where a less expensive technology is required is $ 4,553,640/facility (2019 dollars).
The department assumed the Annualized Capital Cost Factor (20 years at 5% discount) = 0.08 is applicable to scenarios where less expensive technology is required.
The department estimated annual capital cost per facility for scenarios where a less expensive technology is required is $364,291/facility/year = $4,553,640/facility (2019 dollars) x 0.08 (2019 dollars).
More expensive technology.
The department used estimates for recirculating systems that the EPA used for the rule (see References below).
EPA estimates that wet cooling towers will cost $263/gpm (2009 dollars) of water (for installations of average difficulty). Addition of plume abatement technology is predicted to increase capital cost by $120/gpm (2009 dollars).
Based on a small facility with 125 MGD the EPA based estimate per is $23 million /facility to $33 million /facility (2009 dollars) per facility or $27.5 million /facility to $40 million /facility (2019 dollars).
In conclusion, the department estimates an annual capital cost for scenarios where a more expensive technology is required is in the range of $27.5 million to $40 million (2019 dollars).
The department used the low value of the range as an estimate of capital cost for scenarios where a more expensive technology is required.
The department estimated capital cost per facility for scenarios where a more expensive technology is required is $27.5 million /facility (2019 dollars).
The department assumed the Annualized Capital Cost Factor (20 years at 5% discount) = 0.08 is applicable to scenarios where more expensive technology is required.
The department estimated annual capital cost per facility for scenarios where a more expensive technology is required is $2,200,000/year/facility = $27,500,000/facility x 0.08.
COST PER YEAR
Cost per year = annual capital cost + O&M cost per year
