SCREENWASH RETURN WATER 

MODIFICATION STUDY 

GLENWOOD AND PORT JEFFERSON 

POWER STATIONS 

KEYSPAN CORPORATION 

April 1,2002 

BY 

KeySpan Environmental Engineering 

and Compliance Department 

175 East Old Country Road 

Hicksville, NY 11801 

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water empties onto the beach along side the screen house foundation. The trash basket is 

emptied from time to time to dispose of accumulated debris. 

The objective of the proposed conceptual fish return scheme, as depicted on drawing 

PJPSM-FY-99000 (attached) is to safely return any sea life caught in the intake screen 

wash system back to Port Jefferson Harbor. This would be accomplished by removing 

the trash basket from the intake sump area located on the north side of the intake and 

replacing it with a stainless steel open trough. The trough would route the discharge from 

the screen wash trench, across the sump, to a 24''dia. fiberglass pipe supported on the 

outside of the sump structure. The pipe, running in an easterly direction, would deliver 

the discharge and any included sea life to a point at least 14 feet beyond low tide, thereby 

insuring safe return to sufficient water depths. The pipe is on an approximate 1YOslope 

and is equipped with two y-sections for clean out in the event the pipe becomes clogged. 

The total length of the return pipe will be approximately 120 feet. It will be supported by 

brackets mounted on the existing sheet steel bulkhead at an elevation of approximately 

+8.5'(MLW). 

Upon approval of the conceptual fish return scheme and receipt of any required wetlands 

permits, final construction drawings will be prepared. Depending on availability of 

KeySpan construction forces, material procurement and contractor selection would then 

be initiated, with construction to be completed approximately two months after start of 

work. 

AC Gross 

4- 1-02 

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112 

/-----

ELEVATION “D- D’ 

Figure N-13 Intake StrUCtUre,Units 4&5 

Glenwood Power Station 
Keyspan Corporation 

Environmental Engineering Depadment 

175EasiOId Countrv Road 

Hicksville,New York.11801-4280 

June 21,2002 

Mr. Larry Wilson 

NYSDEC 

Bureau of Habitat 

625 Broadway, 5' Floor 

Albmy, NY 12233-4756 

Re: Intake Mitigation Projects at Keyspan Power Stations 

Submission of Study of Travelling Screen Continuous Operation 

Dear Mr. Wilson: 

Pursuant to Item 2 of our letter of March 29, in which we agreed to conduct and provide 

certain studies requested in your letter of February 12,2002, please find enclosed our 

report on the feasibility of increased screen wash frequency at the Port Jefferson, 

Glenwood and Far Rockaway power stations. Northport and EF Barrett presently operate 

their screens in a continuous mode. 

The report concludes that, while more frequent screen operation is feasible, wear and 

tear, maintenance, electrical consumption and maintenance are all increased. In addition, 

a number of equipment upgrades would be required to support more frequent operation. 

Added costs for continuous operation would be $110, 577 the first year and $79,777 per 

year thereafter. 

In order to achieve maximum effectiveness in reducing fish impingement exposure times 

while minimizing equipment wear and operational costs, we examined the fish 

impingement data collected during the extensive monitoring programs conducted in 

1976-77. These data are summarized by month for each plant in the attached table. This 

indicates that a majority of impingement at the three plants occurs during relatively few 

months. Based on these data, we propose to operate the screens wash systems 

continuously during the months of October, November and December at Glenwood and 

Port Jefferson and during May and November at Far Rockaway. 

If you have any questions on the above, please call me at 5 16-545-2561. 

Very truly yours, 

A. Christopher Gross 

Enclosures 
MONTHLY FISH IMPINGEMENTTOTALS, 1976-77 DATA 

JANUARY 

FEBRUARY 

MARCH 

APRIL 

MAY 

JUNE 

JULY 

AUGUST 

SEPTEMBER 

OCTOBER 

NOVEMBER 

DECEMBER 

TOTAL 

FAR ROCK GLENWOOD PORT JEFF BARRETT NORTHPORT 

(1 UNIT) (2UNITS) (2UNITS) (2 UNITS) (3UNITS) 

1976 1976 1976 1976 1976-77ave 

448 240 624 9139 5342 

242 864 756 1379 2785 

240 344 168 4996 1685 

1528 452 413 24215 1087 

2484 320 856 8062 1763 

1216 546 315 2751 1198 

1390 720 712 2891 677 

1804 148 632 2749 2786 

0 259 880 1649 1814 

1472 1346 3000 28001 1100 

2064 15880 10808 63496 2969 

1040 3192 7392 7348 4805 

13928 24311 26556 156676 28011 

Note: Barrett and Northportscreens operate continuously at present 

FR, GW and PJ proposed to operate continuously in months bolded 

ACG 6/20/02 
June 20,2002 

Continuous Traveling Screen Operation Feasibility Study 

Far Rockaway, Glenwood, Barrett, Northport and Port Jefferson Power 

Stations 

Purpose: 

This study was conducted, at the request of New York State Department of 

Environmental Conservation, to evaluate the feasibility of running the 

’ Traveling Water Screens in a continuous mode rather than intermittent 

operation. DEC is concerned that any fish impinged on the screens may be 

adversely affected by extended exposure during periods when the screens 

are not operating. To conduct this study, equipment upgrades were 

investigated, additional maintenance and power costs were calculated and 

reliability issues were looked at. 

The report attempted to answer the questions; can we operate the Traveling 

Screens continuously, if so, what upgrades would be necessary and then, 

what would the additional costs be? 

Executive Summary: 

Continuous operation of Traveling Screens decreases the time to failure of 

the wear components and increases the electrical power consumption. 

Although the drive motors for the screens vary between 3/4 hp and 3 hp, the 

larger power usage comes fi-om the screen wash pump motors that vary 

between 40 to 50 hp, by design. If screens for all Keyspan’s Long Island 

stations were run continuously instead of the present operation, the 

additional auxiliary power costs would be $39,399/year. 

The report details equipment upgrades available for continuous operation. 

A major portion of the upgrades was conducted a few years ago. All our 

power stations now have fiberglass baskets with stainless steel screening 

material. This reduces the weight of the baskets by 40%, resulting in less 

power consumption and less loading on the headshaft bearing. The original 

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specification for headshaft and footshaft bearing material was bronze. 

Bearing material upgrades are now available and are recommended in this 

report to provide increased wear protection. Most of our plants still have 

bronze bearings. The differential material cost for the improved bearing 

material is $1400/screen or $30,800 for all 22 screens for the Long Island 

plants. Bearing replacements could be made during normal maintenance 

periods, when the bronze bearings would have been replaced fi-om normal 

wear. 

Increased maintenance would include additional time to clean screen wash 

nozzles, to clean screen wash pump strainers and time for increased 

lubrication frequencies. Additionally, increased attention will need to be 

given to assure screen alignments are true. Misalignments can cause 

accelerated wear. This report estimates the cost for additional preventative 

maintenance labor would be $40,378/year, if all screens were operated 

continuously, as opposed to the present operation. 

During the plant equipment inspections and discussions with plant 

personnel, it was determined that continuous operation for extended periods 

was a feasible operation for all our plants. Northport Power Station and the 

Barrett Power Station already run their screens mostly in the continuous 

mode. These two stations have 12 screens out of the system’s 22 screens, 

therefore we already run more than half of Long Island’s Traveling Screens 

mostly in the continuous mode. 

Since Northport and Barrett already run their screens mostly in the 

continuous mode, a decision to operate all screens continuously would 

directly affect Far Rockaway, Glenwood and Port Jefferson. The increased 

differential costs for auxiliary power, upgraded bearing material and 

increased labor costs would initially cost $1l0,577/year. This number 

includes the improved bearing upgrades for all our plants. 

Recommended modifications can be made during the routine maintenance 

outages and would not preclude continuous operation, during peak 

impingement periods, at this time. 

A review of the 1976-77 fish impingement data at the plants indicates a 

peak in impingement abundance at Gfenwood and Port Jefferson during 

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November, with elevated numbers also during October and December. Far 

Rockaway numbers peak during the months of November and May. 

Therefore, maximum benefits, in terms of reduction of impingement 

exposure, would be obtained if the Traveling Screens were runin the 

continuous mode during these specific months. Northport and EF Barrett 

already operate their screens mostly in the continuous mode, so exposure 

times there are presently minimized. 

Study Methods: 

Equipment upgrade recommendations were discussed with the Traveling 

Screen manufacturers. Contacts were made with other utilities that operate 

their screens continuously. They were questioned on what equipment 

changes were performed and what problems were encountered. The 

original specifications for our Traveling Screens were looked at. Equipment 

inspections and personnel interviews were conducted at all our power 

stations. Plant personnel discussed their present maintenance concerns and 

their operational methods. Finally, vendor manuals were referred to in 

order to compare manufacturer’s recommended maintenance intervals to 

those performed in the field. 

Manufacturers Recommendations: 

Equipment upgrades recommended by the manufacturers include stoody 

bearings for the footshaft and Thordon bearings for the headshaft. KeySpan 

has already converted all our baskets to fiberglass baskets with stainless 

steel screens. 

Vendor Manual Recommendations: 

Normally screens should be operated when 6” differential exists. With up 

to a maximum differential of 30”, the screens can still start with a solid 

shear pin. If the screens are operated continuously, they should be run at 

the slowest speed possible to maintain a 6” differential. With 100%clean 

screens there will be a 0.I3-foot head loss across the screens, however with 

70% clean screens there will be a 0.30-foot head loss. 

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Electrical Power Consumption: 

Assumed a fuel cost of $3.50/rnillion BTU resulting in an auxiliary power 

cost of $O.O3248/k~-hr: 

Total: 22 screens continuous operation = $4,461 .%/year 

Total: 11 screen wash pumps continuous operation = $101,945.39/year 

The total auxiliary power costs for the present operation, where Northport 

and Barrett run mostly in the continuous mode and the remaining plants run 

12.5% of the time is $67,008. 

The added auxiliary power costs to run all the plants continuously is 

therefore $39,399. 

ConclusionsRecommendations: 

The disadvantagesof operating the traveling screens continuously include 

increased wear on the bearings and chains. This increased wear requires 

more frequent greasing and inspections. To counter some of the wear on 

the bronze bearings, upgraded materials of construction should be used, 

specifically Thordon material for the upper, headshaft bearing and Stoody 

material for the lower, footshaft bearing. These upgrades can be done 

during normal maintenance outages, since the bronze bushings on the 

screens now are acceptable for the interim. The improved materials will 

provide for longer intervals before replacement. For all the screens on the 

Long Island plants, total material upgrade costs would be $30,800 or 

$1,40O/screen. The carrier chain and drive chain will need to be inspected 

and adjusted more frequently. With proper inspections, lubrication and 

adjustments, the screens can be maintained at the same level of reliability. 

Continuous operation will increase the auxiliary power consumption, 

mainly due to the screen wash pumps. The additional auxiliary power costs 

are estimated at $39,399, if all the screens are run continuously, over the 

present operation. 

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Continuous operation will increase the labor required to clean the spray 

nozzles more often, clean the screen wash strainers more often, increase the 

lubrication schedules, and increase the time to make screen inspections and 

alignments. The time required for the IO screens at Far Rockaway, 

Glenwood and Port Jefferson were estimated at an additional one-man day 

per month per screen. Using a loaded labor rate of $42.06/hr, this 

calculated out to be $40,378/year. 

The added cost to run all our traveling screens in the continuous mode, over 

the present operation is estimated to initially cost $1l0,577/year and then 

$79,777/year thereafter for power and labor. 

General items required for increased reliability include the following: 

1- Thordon bearings for the headshaft 

2. Stoody bearings for the footshaft 

3. Increased screen adjustments (chain tension and shaft alignment) 

4. Increased lubrications/inspections 

5. Fiberglass baskets (complete) 

In summary, KeySpan has concluded that continuous operation of Traveling 

Screens, during periods of peak impingement, is a feasible operation with 

the existing screens. 

In order to maximize the benefits of increasing traveling screen operation 

and minimize the additional wear, while providing maximum benefit in 

terms of reducing fish impingement duration during times of maximum 

impingement, plans could be made to runthe screens at Glenwood and Port 

Jefferson continuously during the months of October, November, and 

December, and at Far Rockaway during the months of November and May. 

Although Barrett and Northport Power Stations already runs their screens 

mostly in the continuous mode, the most critical months for Barrett with 

respect to impingement are April, October and November. The most critical 

months for Northport are November, December, January and February. 

RWJ, 6-20-02 

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