C. SCOTT VANDERHOEF
County Executive

COUNTY OF ROCKLAND

SEWER DISTRICT NO. 1

4 Route 340

Orangeburg, New York 10962

(845) 365-6111

Fax. (845) 365-6686 DIANNE T. PHILIPPS, P.E. Executive director

July 7, 2005

Mayor John Layne and Board of Trustees Village of Airmont

321 Route 59-P.O. Box 578 Airmont, NY 10982

Re: Village of Airmont

Sewage Overflows/Capacity

Dear Mayor and Board of Trustees:

The following is in response to your letter dated June 24, 2005. First, I will address the four points contained in your letter, Second, I would like to comment on some of the information contained in the packet enclosed with your letter.

Your first and second points refer to our Ramapo Interceptor that begins on South Monsey Road in the old railroad bed just south of Christmas Road. The force mains from our Tallman and Twin Lakes pump stations discharge at this point. During extremely heavy rain events, we have experienced dilute sewage overflows at the above location.

The Sewer District has documented five overflows over the last six years on South Monsey Road beginning with tropical storm Floyd in September of 1999, There may have been events prior to this date but were not researched for this letter. All have been due to heavy rain events and all have been reported to the regulatory agencies verbally and by written report. Following is a list of overflow' occurrences along with the spill number assigned by

the NYSDEC.

Date

NYSDEC SPILL #

REASON

9/16/1999 Over 10 inches of rain
12/12/2003 0310538 Heavy rain, snow melt, frozen ground
12/24/2003 0310980
9/18/2004 0406737 Extremely heavy rain in excess of 4 inches
0406739
4/2 & 4/3/2005 0500077 Heavy rain event of 3 to 4 inches following
0500079 a previous heavy rain event on
0500080 March 27, 2005.
0500099

Your letter states that there was an unreported overflow on December 29, 2003. The Sewer District has no report of a sewage overflow on this date. According to our phone logs and records, we have no reports of an overflow on South Monsey Road. It is highly unlikely that an overflow occurred on December 29, 2003 as it did not rain again after the event on December 24th until a trace amount fell on December 30, 2003. Please see the attached rain data from United Water.

I believe your third point refers to the Sewer District's telemetry system. The telemetry system transmits alarms from our 22 pump stations to our wastewater treatment plant in Orangeburg, which is manned 24/7. We receive alarms for equipment failures and--high wet well levels, We also receive status points for generators and wet well levels. When an alarm is received, Sewer District personnel are dispatched to the pump stations, We lost some of our data gathering functions in 2000 but not the ability to transmit alarms. We have never had any kind of overflow sensors in the sewer lines other than temporary flow meters used for flow studies. The existing telemetry system will be replaced in an upcoming capital project.

The Sewer District has cleaned and televised the entire length of the Ramapo Interceptor, Many rocks and boulders were removed. We will be developing a hydraulic model of the interceptor to assist us in planning future upgrades. The Sewer District also does testing and sealing work in the sewer lines and manholes to reduce inflow and infiltration during rain events.

I hope the above addresses the issues raised in your letter, Following is a discussion regarding the material enclosed with your letter.

Some of the material refers to overflows on Hillside Avenue. The interceptor on Hillside Avenue receives the flow from our Cherry Lane pump station. The Sewer District is aware of one overflow at this location which occurred on June 12, 2003 due to a blockage caused by an odor control dish that had fallen into the interceptor, If residents have seen the manhole overflow on several occasions, it was never reported to the Sewer District. Our field crews have never witnessed any capacity related overflows on Hillside Avenue. Our pump station crews routinely drive on Hillside Avenue when checking our four pump stations that are in the area.

I believe there were two references to our Saddle River pump station. The letter from Peter Strasser includes photos of a manhole chamber behind the pump station. Since upgrading the Saddle River pump station in the mid 1990's, the Sewer District is only aware of one capacity related overflow event which occurred on April 4, 2005. This was due to the previously mentioned heavy rains of March 27th and April 2"d through April . The pump station generally operates in an on / off mode and is not under capacity.

The material included a sketch and a few diagrams showing a size and / or location of our collection system. The sketches and diagrams are not accurate and appear to be taken from a preliminary facility plan.

While the Sewer District considers all overflows to be unacceptable, at times, they are unavoidable. Separate sanitary sewers are designed to convey peak sewage flows with an allowance for infiltration and inflow of storm and ground water. They are not designed to carry storm water from a heavy rain event that causes flooding. Enclosed is a copy of the letter from Bradley M. Campbell, Commissioner, NJDEP, that speaks to this issue.

If you need any additional information, please do not hesitate to contact me and I will be happy to meet with you at your Board meeting on July 18th.

Very truly yours,

Diane Philipps, P.E. Executive Director

DP/ld Encl.

Cc: C.S. Vanderhoef C. St. Lawrence M, Saber

Pile: Village of Airmont / with attach. Reader

UNITED WATER NEW YORK

OPERATIONS DEPARTMENT - SCADA
RAIN DATA

December-2003

STARTING

RVWF

HILLBURN

RAIN GAUGE

RAIN-RVWF

SPRING VALLEY

WELL FIELD

RAIN GAUGE

RAIN-SVWF

LAKE

DE FOREST

RAIN GAUGE

RAIN-LK

THIELLS

WELL FIELD

RAIN GAUGE,

RAIN-THWF

TAPPAN

WELL FIELD

RAIN GAUGE

RAIN-TAP

DAY

INCHES

INCHES

INCHES

INCHES

INCHES

1-Dec-03

0.00 0.00 0.00 0.00 0.00

2-Dec-03

0.00 0.00 0.00

0,01

0.00

3-Dec-03

0.00 0.00 0.00 0.00 0.00

4-Dec-03

0.00 0.00 0.00 0.00 0.00

5-Dec-03

0.15 0.15 0.20 0.19 0.19

6-Dec-03

0.27 0.13 0.47 0.31 0.23

7-Dec--03

0.00 0.00 0.01 0.00 0.00

8-Dec-03

0.00 0.00 0.00 0.00 0.00

9-Dec-03

0.00 0.00 0.00 0.00

0,00

10-Dec-03

0,14

0.00 0.00 0.00 0.00

11-Dec-03

2.22 1.48 1.80 1.80 0.84

12-Dec-03

0.00 0.00 0.00 0.00 0.00

13-Dec-03

0.00 0.00 0.00 0.00 0.00

14-Dec-03

0.96 1.17 1.03 1.25

0,85

15-Dec-03

0.02 0.01 0.06 0.03 0.01

15-Dec-03

0.00 0.00 0.00 0.00 0.00

17-Dec-03

0,90

0.67 0.78 0.95 0.63

18-Dec-03

0.00

0,00

0.00 0.00 0.00

19-Dec-03

0.00 0.00 0.00 0.00 0.00

20-Dec-03

0.00 0.00 0.00 0.00 0.00

21-Dec-03

0.00 0.00 0.00 0.00 0.00

22-Dec-03

0.00 0.00 0.00 0.00 0.00

23-Dec-03

0.00 0.00 0.00 0.00 0.00

24-Dec-03

2.31 2.28 2.00 2.80 1.54

25-Dec-03

0.00 0.00 0.00 0.00 0.00

26-Dec-03

0.00 0.00 0.00 0.00 0.00

27-Dec-03

0.00 0.00

0,00

0.00

Q.00

28-Dec-03

0.00 0.00 0.00 0.00 0.00

29-Dec-03

0.00 0.00 0.00 0.00' 0.00

30-Dec-03

0.01 0.01 0.01 0.02

0,01

31-Dec-03

0.00 0.00

0.00

0.00 0.00

AVERAGE

0.23 0.19 0.21 0.24 0.14

# DAYS

31

31

31

31

31

MINIMUM

0.00 0.00 0.00 0.00 0.00

DAY

01 Dec

01 Dec

01 Dec

01 Dec

01 Dec

MAXIMUM

2.31 2.20 2.00 2.80 1.54

DAY

24 Dec

24 Dec

24 Dec

24 Dec

24 Dec

TOTAL

6.98 5.90 6.36 7.36 4.30

UNITS

INCHES

INCHES

INCHES

INCHES

INCHES