New York State Department of Environmental Conservation 

Division of Air Resources 

Bureau of Air Quality Planning, zn<~ Floor 

625 Broadway, Albany, New York 12233-3251 

Phone: (518) 402-8396 • FAX: (518) 402-9035 

Website: www.dec.state.ny.us 

Mr. Richard Ruvo, Chief 

State Implementation Plan Section 

Air Programs Branch 

May9, 2006 

United State environmental Protection Agency 

Region 2 

290 Broadway 

New York, New York 10007-1866 

Dear Mr. Ruvo: 

Denise M. Sheehan 

Commissioner 

We have reviewed your March 8, 2006 letter regarding the Madison A venue air quality 

monitoring data. As you had characterized correctly, the data collection does not meet the 

requirements of 40 CFR Part 58; and as such, would not be considered as valid for use in 

regulatory programs. Mr. John Seitz's memorandum of March 22, 1997 entitled "Agency Policy 

on the Use of Special Purpose Monitoring Data" further affirms this position since the ambient 

monitoring was conducted under special purpose monitoring conditions and does not meet EPA's 

requirements related to siting or method. 

We have enclosed a draft report which includes an analysis and review ofPM10 

monitoring results from the last 18 years. We believe this report is suitable for the purposes of 

showing that the PM10 data from the last several years are below the PM10 standard. 

We respectfully suggest that the enclosed draft report supports a clean data finding which 

will moot further PM10 SIP work and the associated nonattainment designation. We note that 

EPA has recently approved a clean data finding for two areas in Arizona, the Ajo nonattainment 

area finding was proposed at 71FR6437, February 8, 2006 and announced as a direct final at 

71FR6352; The Yuma nonattairunent area finding was proposed at 71FR13063, Marchl4, 2006 

and announced as a direct final at 71FR13021. We request your review of this report and look 

forward to your comments. 

61 :8 ~~ S I A'IW 90DZ 
Please contact Matthew Reis, P.E., at (518) 402-8396 if you have any questions. 

Enclosure 

cc: M. Reis 

D. Shaw 

J. Higgins 

C. McCarthy 

G. Sistla 

P. Lavin 

H. Felton 

M. Sheehan 

W. Pienta 

, s;cererJbc>t.v--\P' 

James Ralston, P.E. 

Director 

Bureau of Air Quality Planning 
New York State 

A Review of 

Inhalable Particulate 

(PM10) 

Air Quality 

. 

In 

New York County 

(Manhattan Island) 

1988 to mid-2005 

Department of Environmental Conservation 

Division of Air Resources 

Air Quality Planning 

Draft 

May 9, 2006 
This report was authored by W.J.Pienta, with the aid and assistance of K.Civerolo, R Twaddell, H. Dirk 

Felton, S.H. Mo, J.Kent, and G.Sistla. 

. 
Introduction 

Ambient measurements of inhalable particulate matter (PM10), have been 

carried out routinely across the state of New York since 1988. Based on these 

measurements, the USEPA noted that only one of the areas, New York County, 

NY was in nonattainment or was exceeding the annual form of the NAAQS of 50 

ug/m3. Although measurement of ambient PM10 levels in New York County were 

made at 8 monitoring sites since 1998, it should be noted that the data at any site 

were often limited to less than 3 years due to logistic and other reasons, thereby 

requiring a careful asses~ment of the entire data base. In this study, we 

attempted such an assessment utilizing descriptive statistical tools and time 

series analysis in examining if the measurements exhibit exceedance of the 

annual and daily PM, NAAQS, which are 50 and 150 ug/m3, respectively. Our 

analysis indicates that overall PM10 levels exhibit a downward trend in the county, 

and that the area is below the annual NMOS. Examination of the measured 

PM1o levels, including special purpose monitors (SPM), indicates that all the sites 

are below the NMOS level, even though these measurements may not meet all 

the criteria set forth under SLAMS/NAMS operational protocols. 

This review looks at all available data, whether or not specific regulatory 

requirements are met. In some cases, data may not have met sufficiency criteria 

spelled out in federal regulations. In other cases, data may not have been 

gathered using reference or equivalent methods. 

Monitoring Sites 

Figure 1 (the figure number corresponds to the page number of the 

accompanying "graphics PDF" file) provides two panels; Fig. 1 (a) shows the 

location of all historical monitors in NY County, while Fig.1(b) shows only the 

current PM1o monitoring sites. 

Data Review 

Descriptive Statistical Summary: Figure 2 displays a summary of all 

data available from PM10 sites in NY County since 1988. In the columns to the 

left of the graphic are the named site and, then, a numeric designator for the 

specific site. Each of these sites has a designation of 36-061-xxxx. This 

identifies the state (36), and county (061) within the state, and then the specific 

monitoring site (four digits) 

The graphic consists of a series of ubox and whisker" plots (also 

simply called a box plot) that summarizes the data from each of the sites. The 

data are divided into four areas of equal frequency, called quartiles. The 

interquartile range (IQR), which determines the length of the box, is the 

difference between the third and first quartiles. The length of the box bounds the 

middle 50% of the data, and is a visual measure of the dispersion. For those of 

us unaccustomed to interquartile ranges as a measure of variability, standard 

deviations are also listed in Table 1 for each site. The median is drawn as a 

vertical line, while the average is plotted as a plus(+). To establish the bounds 

on potential extreme values and outliers, a lower (left) whisker is drawn from the 

lower quartile to the smallest point that is still within1.5 interquartile ranges from 
that lower quartile. In a similar manner, the upper (right) whisker extends out to 

the largest point within 1.5 IQRs. Values between 1.5 & 3.0 IQRs are plotted as 

individual points, and data beyond ± 3.0 IQRs are plotted as points with a plus 

through them. A legend in the lower right of Figure 2 summarizes these features 

of the box plots presented here. 

Also listed in Figure 2, to the right of each individual box plot and in line 

with each site, are (1) the number of samples, (2) the time span of the monitoring 

effort, and, (3) sample frequency. The standard for the annual form of the 

NAAQS is highlighted along the horizontal axis and a vertical line is established 

at the level of 50 1Jg/m3

• This level is shown as an indicator, and some caveats 

on interpreting the one and only average that is above this standard are 

discussed below. Table 1 provides numerical values for the average, median, 

and standard deviation. 

TABLE 1: Summary Statistics 

Site 10 Count Average Median Standard 

Deviation 

0002-CCNY 35 29.9 26.0 12.9 

0010-Mabel Dean 4,976 22.9 19.8 13.4 

0056-P.S. 59 478 34.7 31.8 16.3 

0062-Canal St. P.O. 427 25.4 23.2 11.8 

0069-Bowery Savings 211 42.2 39.0 17.9 

0077-Mad. Ave Research Site 590 51.9 47.6 21.8 

0093-37 St. 53 41.3 37.0 21.2 

0095-Canal@. Broadway 133 46.9 44.6 17.4 

0123-Albanv St. 10,625 27.0 23.4 16.4 

0125-Pace Plaza/Park Row 24,982 24.5 21.3 14.1 

0130-23 Wall St.@ Broad 5,335 27.4 24.9 13.8 

From the array of box plots in Figure 2, two distinct features are important 

to note. First, and most germane to the point of this exercise, is that Madison 

Avenue has a long-term average that exceeds the NAAQS in its annual form. A 

number of points with regard to that simple statement must quickly be made. 

First, from its inception, this site has been subject to some controversy over its 

location insofar as its use beyond a research site (a.k.a. a special purpose 

monitor). Recent agreements between NYS DEC and USEPA acknowledge its 

continued value as a research site, but admit that, as a special purpose monitor, 

the site does not meet requirements for use in non-attainment 

designations/attainment demonstrations. Second, there is a penchant for making 

comparisons to the NAAQS where data exists, despite the inapplicability of the 

Madison Ave. site for purposes of judging attainment. So it is with the 

Department's technical staff as well. As subsequent figures will show. more 

recent data, even for the Madison Ave. site, remain below the NAAQS. Other 

sites are lower still. Furthermore, the long term average for the Madison Ave. 

research site cannot be considered the expected value for future measurements 

at this site, in light of a downward trend in the recent data. The significance of 
the trend should be investigated further, but that is beyond the scope of this 

effort. 

Another feature of the box plots is the ease with which stations that report 

hourly values can be distinguished from those stations collecting 24-houraveraged samples. The ~extra-long~ tail of the ~extretnen right side of the 

distribution of values is the tell-tale sign of hourly data, and should remind us that 

PM10 measurements tend towards a lognonnal rather than a normal distribution. 

More large values are expected in a lognormal distribution, so that statistical 

tests based upon a presumption of normality will judge far more of the values in 

the right-hand tail to be "outliers" when they are not necessarily outliers in a 

lognormal distribution. For these and other practical reasons, this review does 

not dwell on statistical tests for the significance of the trend lines. 

Times Series Analysis: Figure 3 is a time series of all the available daily 

data (Figure 4 presents the hourly data). Figure 3 contains the data from 8 

different sites in 5 so-called "small multiples", meaning that the five graphs share 

a common X-axis covering a time span from late 1987 to the recent past. In this 

particular case, the range or span of theY-axis is the same in all five plots as 

well. The five graphs are labeled (a) thru (e) along the right margin. Having a 

common X-axis allows for easy comparisons across several sites for the same 

time period by scanning up and down the vertical axis. None of the daily 

averages exceed the daily form of the NAAQS (150 ~g/m ). For each of the eight 

site-specific time series, a trend line that represents the best straight line fit thru 

the data is also drawn. The averages are given in Table 1. Two points need to 

be made with regard to the trend lines. First, if the trend is real (i.e. significant), 

then the average is not the best measure of the expected value of a future 

measurement or series of measurements. The second is that one of the 

properties of a least-squares regression line is that the mean value is a point on 

the trend line. So, if a trend line is entirely below the NAAQS, it provides 

incontrovertible evidence that the site is in attainment over the span of time 

covered (independent of whether such a trend line is statistically significant). 

Thus, it should be clear from Figure 3 that all sites, except Madison Ave, were in 

attainment. Furthermore, the more recent Madison Ave. data, for which a 

separate trend line is drawn (see Fig. 3(d)). is below the NAAQS for the most 

recent years (the last four years, to be specific). A closer look at only the most 

recent Madison Ave. data appears as Figure 6. 

Figure 4 presents hourly data from four differing sites. Only Pace 

Plaza/Park Row site continues to sample at present, although it, too, is a special 

purpose monitor. The salient feature of Figure 4 is that all four sites were well 

below the annual NAAQS, since each of the trend lines is well below the NMOS. 

Hourly data contain more short-term but elevated concentrations (which gives 

rise to a lognormal distribution mentioned earlier), and creates the long tails 

discussed in relation to the box plots of Figure 2. This is reinforced by the 

magnitude of theY-axis range or span that is necessary to fully display all the 

measurement values. To assist in making numerical and visual comparisons 

with the daily (24 hour average) data shown in Figure 3 for the other sites, the 
hourly data was reduced to daily averages. No minimum threshold for the 

number of hourly samples was established for this exercise. Some days have 

averages comprised of as few as 8 or 9 hours of data. All daily averages are 

plotted in Figure 5. None of these daily values exceeds 150 ~g/m . Trendlines 

are also presented. 

Figure 6(a) redraws from Figure 3 only the most recent data for Madison 

Avenue, and superimposes a second-order trend line through these daily values. 

In Figure 6(b), the daily values are reduced to annual averages. Annual 

averages from Canal St. P.O. (calculated from the daily values in F'ig. 3(c)) are 

plotted as well. These annual averages can be compared to the annual NAAQS 

that is drawn in as a long red bar across the plot. 

Conclusion ~ 

New York County has measured attainment at the Canal St. P.O. for the 

past three years. Two other special purpose monitors, one measuring street 

level, traffic-related particulate, and the other measuring particulate ,upwind of the 

World Trade Center remediation and reconstruction efforts, also are measuring 

PM10 that is below the NAAQS. New York County should be officially declared to 

have attained the standard by US EPA. 
(a) Approximate Locations of 

PM10 Monitors in Manhattan 

from 1988 to the present 

<- § 

r.J 

<:."' 

-'--0 

s 

e-f--- CCNY 

v 

37th St. 

W of 7th Ave. 

Canal St. P.O. 

Pace Plaza/Park Row 

Albany St. 

() 

I ,v---- P.S. 59 

Mad tson Ave. 

Bowery Savings Bank 

._\---._ Mabel Dean H.S. 

Canal St at Broadway 

Wall St. at Broad St. 

(b) Approximate Loca

PM10 Monitors in Man

as of February 2006 

.:;;.. 

Q, 

Canal St. P. 0. 

....._____ 

() 
Box-and-whlaker plote; for PM10 data from all altea In NY Count

Site loCJJtlon & AQS 10 "---.------- .,-------r ,-------,---- .. 

CCNY 0002 jO n=35 

Mabel Dean 0010 .. • n=4976 from tt6.89 to 6.14.0

P.S.59 0056 f+--lJDIJ <DJ n=4

Canal St. P. 0. 0002 • • n=A2

Bawery Ssvlnge 0069 I o • n"'21

Mad. Ave. Reeearch 0077 I e + n,590 from 1.1.93 to12.31.98 

37th St. 0093 0 0 • n""5

Canal@ 6'way 0095 n=13

Albany St. 0123 e--[EH -·-· • • • • n""1

P8ce Plaz.l'I/P8rk Row Ot25 I I n"'2

23 Wl!lll St. " Broad 0130 . ... . . n=5,3

I -------'------

_ _l_ 

0 .A 100 200 300 

Annual 

NAAQS 

Sam pi• Valuo 

notes: 

1. not all of the: data summarized here is In the AQS system 

2. sampling methods may vary within and betwen sites over the time span 

W,J. f'i<m\:6 .. 12706 

LEGEND' 

Q 

box llncompaeeee m

vertical line thru box 

plue elgn lethe aver

whlekllre repreeent ± 

pointe beyond ± 1.5 

beyond 3 lnterquartl
~ 

t 

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1: 

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® 

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2 

PM10 Daity Data ::All NY County sites that reported daity data since 1988 

The Annual form of the NAAQS of 50 f.lg/m3 is highlighted in red in each plot 

150.-------------------------------------------------------------------

100+-------------------------------------~~--------------------------

= 

8/1111987 

=~ --- ;I ...... - -

~,-----------------------------------------------------------

100+------------------------------------------------------------------

50 

0 

(a) 

(b) 

8(1111987 811011990 8/91199'3 81811996 818/1999 8171'2D02 8161'2/)()5 

150 

Cane I St. P.O. (0062) 

100 

:(c) 

50 

0 

... .. ·a;;··--:.= - .. - i- --• 

811111987 8/1011990 81911993 818/199£; 81811999 8f7/'2002 81612005. 

150 

100 

50 

0 

811111987 

150 

100 

·. 

·. !(e) ·. •. 

"'-' p"""" 12706 
t<l 

E 

...... 

l 

s: 

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s: 

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E 

:J 

\1) 

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2 

PMw Hourly Data :: All four NY County sites from 2000 to 2

180 

'·.' l ,: I • • 1 ·,- i' ,, I Park Row:: Pace Plaza 

160 

140 

120 

: • 

• . . 

. • • 

100 

80 

J . 

• . 

' . . • • • c. • 

. • 

I .. 

• . 

60 

40 

20 

0 r 

.... 

-

350 

300 

250 

200 

150 

100 

50 

0 

Mabel 

Dean 

H. S. 

• 

• 

• . 

_..... 

1£,•-31/MIXI 

Albany St. 

• 

• 

.. 

.. . . 

• 

. 

....... 

12.t:'1112W 

Linear trend lines are 

without regard. to whe

significance to the re

is practical significan

cl.-::arly intlicate that t

Mch monitor is well b

of 50 fJgfm3 . 

12o':'J1.'20f"l.!i 
PMw Hourly Data converted to 24 hour (dally) averages 

90 

80 -----------

Park Row:: Pace Plaza 

--· 

70 

60 ..... ---

50 1 ' . ·----·· . . 

-

t{) 40 

E 

" 30 

20 

s:: 

·-

10 

L 

A 4-., ; 0. .0 A :.. 

.. .. .. ....... .. .. ......;_ 

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_____________ , ____ ,___;-..... = -· .. ·... .... *'! .. :-"' '",to... .. :" • ... 

--------------- .. ..... .. .. .. .. 

. . 

IS\ 0 1nr2ooo 

+> 

12131/2000 12131!?.001 12/31/2002 12/31/2003 

s:: 100 

E 90 

L 80 Albany St. (0123) 

IS\ 70 # 

. 

. 

2 60 . 

50 

.. 

-

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• .. 

30 

20 

10 

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---· .... • ':r -

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.... -_:--.;_.·= ... =: ;..'" 

;;,. .. . :------- 

-

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11112000 1213112000 12/3112001 1?.131!2002 
(a) 

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(b) -~ 

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;oo 

Madison Ave. PM1o April15, 2000- December 29, 2004 

Low Volume Partisol- Local Volume Calculation -Includes Flagged Data 

• 

• 

• . . • 

• 00----~--------~----~----------------~~------------------------~ • 

•• 

• 

20 

.. 

.. ·. 

• ·. • 

• 

• 

' 

. 

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~ 

• 

... • 

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• • 

• 

• 

. •• 

• •• ~ 

.. 

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• 

PM10 Annual Averages from Daily Data 

Madison Ave & Canal St. P.O. compared 

• 

• 

• • 

• •• 

• 

• • ..,. • • 

, . • • . . 

. ~ 

. . . . ... ., -. 

• • 

Wr--------------------------------------------------------, 

-

f,r.nu"' 

N,'.AQS 

...;:,.. Line;;;rtrcnd!'nc 

o1" t-nt -;'lvt 

w t----------------------------------------------------,~,c,c,c,,.',o-c,o,c.c,c,c,c,,.-i 

C~nal St. P.O. (0062) 

20 

w 

Date 

NYS DEC W.J f'.,nt,o 4141'2006