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 = $27,500,000/facility x 0.08.
COST PER YEAR
Cost per year = annual capital cost + O&M cost per year
The following table shows the total cost per year based on the above estimates.
Four Categories Showing Estimated Costs per Facility (2019 dollars)
Category of Facility | Capital Cost | O&M Cost | Total Annual Cost Per Year ($/facility/year) |
| Capital Requirements | Capital Cost ($/facility/year) | O&M Requirements | O&M Cost ($/facility/year) | |
1 | Not needed | 0 | ½ of EPA’s average O&M estimate | 65,500 | 65,500 |
2 | Not needed | 0 | EPA average O&M estimate | 131,000 | 131,000 |
3 | Less expensive technology | 364,291 | EPA’s average O&M estimate | 131,000 | 495,291 |
4 | More expensive technology required | 2,200,000 | EPA’s average O&M estimate | 131,000 | 2,331,000 |
The following table summarizes statewide costs based on the above estimates.
Four Categories Showing Long Term Annualized Costs of Compliance Statewide (2019 dollars)
Category of Facility | Count of Facilities in State (#) | Annual Capital And O&M Cost Per Year For Facility In A Category ($/facility/year) | Total Of Annual Capital And O&M Cost Per Year For State For All Facilities In A Category ($/state/year) |
State total for all categories | 28 | NA | 12,971,574 |
Based on these estimates, the long term annual cost to come into compliance with the federal rule for the entire state is $13 million per year (2019 dollars). The total in any 2-year window would be two times the long term annual cost or $26 million for a two year period (2019 dollars).
In conclusion, costs are difficult to estimate because the cost of technology will depend on case-by-case permit decision for each facility. The costs here are based on lower end estimates of likely scenarios.
References:
The department used estimates for O&M cost per year from the following EPA document.
Economic and Benefits Analysis for the Final Section 316(b) Phase II Existing Facilities Rule. EPA-821-R-04-005. February 2004. o
Table B1-4 lists the estimated costs of each of the monitoring, record keeping, and reporting activities described in the EPA report. Certain activities are expected to be more costly for marine facilities than for freshwater facilities.The department used estimates for capital costs for fine mesh screens and very fine mesh screens and travelling screens from the following EPA document.
Technical Development Document for the Final Section 316(b) Phase II Existing Facilities Rule EPA 821-R-04-007 DCN 6-0004 February 12, 2004. o
Figure 1-2 presents the total capital costs of the complete system for fine mesh screens in freshwater at selected offshore distances. Figure 1-7 presents the total capital costs of the complete system for fine mesh screens in freshwater with Zebra Mussels at selected offshore distances. o
Section 2.1 explains how width and depth can be estimated.
