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HomeMy WebLinkAbout20210755 269 Broadway Site Plan Public Comment-From David Biggs, to 2.21.22 EMail Comments on Proposed 269 Broadway Project February 21,2002 To: The Planning Board Saratoga Springs,NY As a resident,I am concerned that several significant technical issues related to the proposed building at 269 Broadway have been overlooked or incorrectly stated in the ApplicanYs submissions. These issues could negatively impact the area surrounding the site if not identified and addressed. This will be a unique building for Saratoga Springs. 1. It is to be built with two levels of underground parking with the lowest 18 to 20 feet below the groundwater level.Thus far, I have been unable to identify one building in Saratoga Springs that has been built so far below the groundwater level. This type of construction might be common in cities such as Boston or NYC but not in Upstate NY. The effects of such construction should be understood and critiqued. 2. In addition,the City is unique for its springs and the presence of an aquifer. Both should be considered for any environmental review. My concerns are summarized as follows: • The SEQRA approval was based on incorrect and incomplete information. Specifically,the recent Revised Geotechnical Report raises major issues never discussed in the SEQRA. Therefore,all the necessary issues for the thorough review of this unique project were not addressed before the SEQRA approval was given. • The Site Plan Application did not list any dewatering needed at the site.The water depth is at least 18 feet. There will be significant dewatering required that could cause settlement to the surrounding properties and City streets, including utilities. The quantity of water to be removed and its effect on the City sewers has not been discussed due to the error in the SEQRA application. • The Storm Water Pollution Prevention Plan incorrectiv stated there was no groundwater yet provided a Geotechnical Report that indicates groundwater. Thus, the SEQRA application was incomplete because it avoided issues related to dewatering including the impact to City sewers and streets by removing excavated material from below the groundwater level. 1 • Handling and transport of the excavated material were not addressed by the Storm Water Pollution Prevention Plan. The wet material and the nearly 2,000 trucks to transport it out of the City are environmental concerns for the City streets, sewers, traffic during construction. • The Geotechnical Report submitted for the SEQRA approval did not address two levels of underground parking. A recent Revised Geotechnical Report does acknowledge the underground parking below the groundwater level but does not adequately address the concerns to City streets, adjacent buildings, and City utilities from the possible settlement due to dewatering during construction or post-construction effects. • Errors by omission in the SEQRA application left the construction of the excavation support system and dewatering systems open to the Applicant. There are several options but each method will have a different impact on dewatering the area, the City streets, adjacent buildings,and City utilities. • Maintenance of traffic and City utilities adjacent to the deep excavations were not addressed in the SEQRA approval either. • The Revised Geotechnical Report does not discuss possible settlement of the City streets, adjacent buildings, and City utilities due to foundation construction activities. • The effect on the aquifer and the historical springs in the area were not addressed by the SEQRA application.The City has been surprised by groundwater issues created by previous projects. Similar problems should not be repeated. • Construction operations,particularly those causing vibrations,must be closely inspected,monitored,and controlled. These concerns are supported by the technical comments that follow. Leaving these to be resolved after the project is approved is not in the best interest of the City and residents. Unless noted otherwise,the following comments include data obtained from information supplied to the Planning Board by the Applicant. State Environmental Quality Review Act(SEQRA) The Planning Board approved a negative SEQRA declaration for the project. The following indicates that the declaration was based upon information that was inaccurate and incomplete. 1. The Site Plan application dated 7-19-21 stated there would be no dewatering(see yellow highlight on Figure 1 taken from the application). Based upon the Geotechnical Reports provided by the Applicant,the proposed building will be up to 20 feet below the groundwater level at its deepest point. 2 D.2. Pro,jcct Operations a.Does ihe proposed action include any excavation,unniug.ox dxedging.durine consmictimi.operatious,or bo1h7 �Yes❑No (Not includiug gei�eral site pre�acation,grading or installariou of utilities oi foundations�vhere all excavatcd materials will remain oiuite) ll�Yes: i.Wl�at is the purpose of die exeavanon or dred�ii�g'?�o construct uncaerground parking garage ii.How much mateiial(i�duding rock,earth,sediments,eu.)is proposed m be removed from d�e site? • Volume(specify tons or cubic yards): n,oao cv • Over what durntion of time? 2 months itt.Describe uamre and charactenstics of materials to be excavated or dredged,and plai�s[o use,manage or dispose oYthem. i�� 4V'ill there be onsite den�atering or}�rocessing of excavated materials? �Yes�No If vcs.describc. ,�.��I�at is the total u-ca to be dredged ox excavnted'? o.s2 acres i�i.What is thc maximnm�rea ro be worked at any one time'? n s� acres rii.Wl�at would be the mnximum deptl�of excavation or dredgiug? zo feel vin.R"ill tlic escavatiou require blastiug'? �Yes�No rx.Smnmarize site reclamation goals and plan: Figure 1—Partial Site Plan Review Application Because the dewatering was incorrectly stated,the follow-up request for a description was never completed.Therefore,the Planning Board has not critiqued any plan for dewatering or processing the excavated material as required by SEQRA. 2. The Storm Water Pollution Prevention Plan (SSWPP)dated July 19,2021,was included with the ApplicanYs Site Plan Application,and stated on p.9"Groundwater was not encountered at the boring locations"(see excerpt below from 3.2 Soils and Groundwater). "Eight(8)borings were progressed at the project site.Boring locations are depicted in Figure 1-1. Results from the infiltration testing are shown in Table 3-1.Groundwater was not encountered at the boring locations.See the geotechnical report in Appendix G." 3 This statement is incorrect.The Geotechnical Report dated 9-15-2019 was included in Appendix G and the borings did indicate groundwater and the report stated that groundwater was at a depth of between Elevation 289 and 292. For reference, the report lists Broadway as between Elevation 302 and 299 and Hamilton Street as between Elevation 293 to 294. Because the groundwater statement was incorrect,the application is incomplete as well. 3.As stated,the Geotechnical Report dated 9-15-2019 provided the groundwater information. However,it was not prepared for the Applicant and did not envision the two levels of underground parking that have been part of the project since inception. However,while the Geotechnical Report did not include the two levels of parking,it did include concerns over dewatering for a building even without two levels of parking. 4. Based on concerns over the issues related to the Geotechnical Report,the City's consultant,CHA,was contacted and made aware of several inconsistencies in the Site Plan Application and the Geotechnical Report.CHA acknowledged the concerns and requested a revised Geotechnical Report by the Applicant.A revised report dated February 1,2022,was produced. This will be discussed in detail later. 5. The ApplicanYs Storm Water Pollution Prevention Plan stated on p.10 that the site is not within an aquifer and provided some mapping in support of this conclusion(see an excerpt of 3.5 following). "3.5 Aquifers The project site is not located within an Aquifer,see mapping in Appendix G." The Storm Water Pollution Prevention Plan provided Figure 2 as follows.The grey area represents an aquifer. I believe the ApplicanYs location of the site is incorrect;it appears closer to Corinth than Saratoga Springs.The red dot is mine as the likely location of Saratoga Springs. 4 � �f . a PRC}JECT ' �� S1TE �,, r r �+ �' �i � ���'�, �-_� �,� ,,� . � � - ��-� �, Figure 2—Project Site from SWPPP Figure 3 map was obtained from the USGS, Unconsolidated Aquifers in Upstate New Vork website.The grey portion is showing aquifer areas. I have provided my interpretation on this as well as the red dot on Figure 2. The Planning Board can decide which map seems more accurate and whether the information indicates an aquifer. 5 dJ _ � - � � � � .� -'�.� , �,� �- � , •��. c � �-� �''^ ;� '-`''� ' � yf �a�� r, .��,1, , .1�'�.:-. � �;- `,� A�#i , - --- - �G � � .�--- � .� — � E� � ��A�R - .t-• t : , `-= �� � �, r�_ , . Figure 3—USGS Unconsolidated Aquifers with Saratoga Springs located Furthermore,a Saratoga Today article from THURSDAY,15 AUGUST 2019 titled"History of Saratoga-Geology of the Mineral Springs"mentions limiting the number of springs in the city to allow the aquifer to build back the groundwater(excerpt below). apex in 4he nunibee of springs in thE eiEy of Saratoga Springs�vith he nuriber at 203_hiany ot th�se sprinqs were pumped to extract carbon dioxide gas from Yhe water ior use in sada fountains in big cities,Thos abuse caused many pf the ariginal springs in the city to go dry.Slate law5 passed in 1948 restricted the use and number af min�ral springs ta just 17 today.Thos restricted number allowe�the ae�uifer over�ime t�bulld back the necessary ground storage to pravide for a stable supply For future use. 6 If the information provided is not conclusive, it does at least raises questions of the designation by the application of no aquifer that the Planning board should resolve. Revised Geotechnical Report dated Februarv 1.2022 The Revised Geotechnical Report now includes the concept of two levels of parking below grade. However,it leads to many more questions that were not included as part of the original SEQRA application yet should be made part of a correct SEQRA application. The report proposes the building be constructed on a mat foundation. The report also lists the following data, some of which was slightly modified from the original report: Broadway Elevation 298 to 302. Hamilton St.Elevation 293 to 295. Proposed ground floor level at Elevation 297. Groundwater level at Elevation 290. The lower level of parking at Elevation 278. Bottom of mat foundation at Elevation 274. Bedrock is between elevation 264 to Elevation 269. Beneath the mat foundation,the report recommends installing a 2-foot base of crushed stone. That indicates the bottom of the excavation is likely to be Elevation 272 or approximately 18 feet below the groundwater level. 1. The new information in the Revised Geotechnical Report further affects the original SEQRA approval. On the Site Plan Application,it listed the depth of dredging as 20 feet(see blue highlight on Figure 1 from the Site Plan Review Application). Based upon the revised report,the actual dredging(excavation)required is 21 to 23 feet near Hamilton Street and 26 to 30 feet near Broadway. 7 2. To illustrate the depth of the excavation required for the proposed building, Figure 4 is the ArchitecYs cross-section to which the previous data has been added. It also shows the expected bedrock elevation. Conservatively, the excavation will be at least 18 feet below the groundwater level. The graphic also includes the excavation support drilled into the bedrock. This will be discussed next. �e�. ��,�.., ., ' Ground floor level 297 Broadway 298 to 302 Hamilton St 293 to 295 Groundwater level 290 . Mat-Lowest parking level 278 • Bottom of excavation level 272 Bedrock elevation 264 to 269 �� a.;r, '�: � ;, �.li - _ ' . .� . '��.,�r�.��:•7�':!� � � � ' , . .- . - � � . . '� ' .`-�;�. 'c �:: . _ �f;. 'F.;r��, , :� -A. . i tt.. .A ,Zi 4 �� �Jr � ' � . • �♦ . . � • �, y�. ..Z� � . �ti�i �. � �� ' � • '1 . � .•».i � P� . . _ .._� . .. .-_ . _� :J...���`� i . ' �� i - . r � .• Excavation support `�6 i fi. r ��i � +` y � �•� r �` ��` �'. � c � � �` i�-`f�r i' : � `, ' � r f� �� 'T I ' � r... '���' •Aj' , ', Y..,z '� '�. 'Afi ,. r .r , ', '� -,-/i . r .r�.1 , • �_ •'�� " � y�, . �'< � � r - 4'a •. !• . .r . S• � _ 4•�� , -y 1 a� �y . 1 � � drilled into bedrock ,!, .+y' . ' -cZ • •X�e; • r. -4! .+�f. r �� -!� .►�(' • � ' s �.«`! � • 1 t� i 'o • ,,,1 ' y• i �� 1 y.• �. � . ,,,l•. t y• i � .l t ��• � � '1 _S� >. r• .+.y. ; . . u.��.a�f. { -�•n. T�. \M��YI. {• �' _•T`� '\V�'�.�1� {. �n. T�.� �\V��a��. �.`rn. r...�V�'��� �e�n. r •'\Y > � -O' . . - , � i t �. as � � ,P' �..'��! � i��� � W ��. �!--„L.y1,. '� i.. y� '�.! ..L.y� ��,�' P'.. �� r t-✓��•�'y � +''�� O ' ,jft, . � 2. r ,jfl t.. ,j�t , � .,jft� . Z. �� .j�t. ,. •„�ft ;� � .j , , .j . �f {J.-'� � �� � !..'r.� �� �J.'s.� '�- �.! w� f :.l 'w1 ,i.� : �.- .t ' ,. ��.��' �, . . .i? ! �. - ��� � �,�' :• ,i � � � :• ��t.� � w �- �� q ♦ � � ..j ♦ . . ��.-. � 4 � v ••��. i� •Z ♦� S��I. t 7 q � .� �. v•� � . �I �• � q �• -� x , • - f � , ��; .. -f � , •... • � �::, 'Y r � j •. 'x'. f i �t •, � .i-'. 2 . ;r.. �! i.. .. � . :r � � 'e�.: � . , . . _� e ��,i,-. � . _a . _i . f�''i�._. . .... . _� � � ►.-.'-� . ,... . ;✓.a';� r� .t� �'. _k.t• Figure 4-Proposed 269 Broadway—Cross-section 8 3. The Revised Geotechnical Report discusses options for the excavation support that were not previously included. It also acknowledges that the choice of the type of excavation support will determine the amount of dewatering required. Some highlights of the Geotechnical are: a. The excavation requires internal support;not using tiebacks. b. Two possible excavation support methods mentioned are a secant wall or soldier piles and lagging. These are not described in detail. c. The report leaves it to the selected contractor to determine the actual excavation support method and dewatering method. d. Driven or vibrated systems should be avoided due to the projecYs urban setting and historic nature of buildings in the area,and the difficulty in adequately seating sheets in the underlying glacial till and bedrock. e. The excavation system should be seated into the bedrock by drilling. So, the report states to avoid vibratory methods (as with sheet piling), but it does allow drilling into the bedrock. It does not offer an opinion as to the vibrations created by the drilling.It also does not detail the effects of the mentioned excavation support methods. 4. Of the two methods excavation methods discussed,each has a different effect on the groundwater level during construction. I offer the following descriptions that were not provided by the report: a. The secant method is typically a series of concrete shafts bored into the ground and socketed into bedrock. Figure 5 graphically shows a cutaway of the installation. These concrete shafts are installed before any excavation is performed;they intersect to form a solid wall. 9 � ar Ko. �:amo J k k� g, -o d,�s«��� o�d 9�..er�oie Rck t C. � '� �_� � lnH i 3 +N�';:3:in3 "_ '' .'. \. Y, �: � . . rl 1- -'1 --�-�:r:� � i - -`l� ,�` �` ��. �y��`�_ , `�•� � _ —_} --=r- �- � _ - __- __ _ _� i--- �lerta0l. �.-.... _ �: � �i si uc��crii_: ' GWda 5V'�.I 1 �� ,:� � , � 4__ �, _ - --- r � - - Figure 5—Secant Wall graphic Figure 6 is a photograph of a completed secant wall after the excavation is completed and the wall is braced at the top. The individual concrete shafts are interconnected and when socketed into the bedrock to provide anchorage and create a cut-off wall to groundwater from the exterior of the site.This is mentioned in the Geotechnical Report. Using a secant wall,the groundwater within the excavation can be dewatered much like a bathtub and the exterior groundwater is theoretically undisturbed. 10 ���'-`" . �r'"F�� `�.. ��' _ – � , �� ' '' – _ ;��- r �- ��',��" ��„_— r�' � l����� ,- , _� ., � -_ a ��+ �� �.� . ,;�_�:.��°;�"�'.`" -- — - _.� . _ . --, � _ _:A,�;� .. � ,. . —��.��_ ,� �. � . � F ' �►^�^ . . . •} � � � � �.�- *- �- �I�: ;� 1 `il .-. � . � � _ ��"- �" Y � � �C •�r� �''"'` a . !! }y � #", [ �x. . r� ' `'�- :�3, f � JF. . � _;' ° _ t -_se..:� "�i•�p �� � ��.lt� - y' - . �T�' -+�' ; � ,._ � �-, � _.'` �A� � � - ,. � � s �Y � � �' Y �. :� � . `" s�. �" �' ._ y � � , . . .-'s.. __ . .•l�~��� ��� •/ .���' �, � _ �_�----- �� � . , r � '..s. ��� . ,�' a, �� �� � � � _- �`-- %.- r ��4 �- ����� ����,G="'�6'� -� - �'J .��� �-�'"�-r '�' ,..E��������7�- s".�,�` ' �� � � `�"'�'��� '�"�'q-'zs:at�.. � � � �� `a� ~-"�- �y�- .�- �.J � - �-�1":.�{� � . ; . _. . ��.: Figure 6-Secant Wall excavated with top internal bracing b. The soldier pile and lagging method is more commonly used. Figure 7 shows an installation.The vertical steel piles are first driven into the ground. For the 269 Broadway project,the geotechnical report states they too should be drilled into bedrock for anchorage. As excavation begins the horizontal boards are installed from the top down. As the excavation proceeds, the horizontal beams are installed as needed to brace the soldier piles.The depth of the excavation shown in the photograph appears to be over 20 feet deep; the 269 Broadway excavation will be between 21 and 30 feet deep. 11 This method is not generally capable of acting as a cut-off wall; the groundwater level needs to be lowered below the proposed excavation and maintained until construction of the deep foundation is completed. ` t _� ` ' - '1.�- h �^[ rr�I caen� ..�°- -- - ` ��� llt1, �e� ] _ , . -r� -, r� � - �r`� :�rl/ �-�� - - - .. . 6.. -• -_" . - � � - �� � � - x�'.�, .� - '�� - .: .RA..T . . ...���---�- - "�:� . ' �-- —-'3��_ `' _.. r ___ .. ; � � -� ._ _. �` '`.r ; i.,� . � � , », - .� _ -T ' . �_ . il � �' s ��� _ � � ' � — — �. � �� �'"AF _�"_ `-' �-� ,� ' -''""^'�,`"�..� 1 , ��j t �; '` f � �:� � -.--�— �' -- �� � �T .. - .#' � �,Y�° y �� ` � � �'r s - .,,. s" .{ r � r _ . � .$ - .•l i�l � � ' � f ',� `. k ,.��� .,., �r r y ;�,.r��r , - S- �':"[ � �?�sz. f -}��1 �' r �+ ,..� � '*�.: �� .� . , ,� rrt ��:w� ��'��, r"��e �'�� % j . ���.+ �.l .'oy� �. +� � s �.� f JJJ U ' e � .r �� � "��I�� �r'� � . s , .r{:�,�q� h,g i r. 4v. *,, �`''r �.„�u:+ . r� ,C��., �;��r{,iq �� ��py�i`���4 � �' � � . A:��.""v,,� e:: � �'r�,; ^'� � � I�V�1. ��' Lpy�y�.� ..ty 1 a+ �`' �`'z �'f 1 � "` e . ,.t° � 1 I i 1; � ��4 i��� ��at�ynt,�,.�'i;' R:y , �a�y,� e r � ,..� ; F ;3.!y { �}��}�i��l�4 �} �{t�;�r �.��.. "�-�R� m-ir �9 �'` . . ,�r��f�?..�;'" 9rlF•.p:'��L'�4�;a43�1{��r,`r'+s."�r,c�� . _ . ' . , .. . '-.. �.,��.;.a Figure 7-Soldier Pile and Lagging 12 The excavation support method that the Applicant selects will be based upon or determined by the dewatering method.The dewatering method will have a significant impact on City facilities. The report makes no mention of the possible settlement of adjacent properties due to dewatering and lowering the groundwater level during construction or post-construction. If the groundwater level is lowered outside the building area, adjacent buildings, sidewalks, streets,and utilities will be affected by possible settlement. Of the two excavation support methods mentioned,the soldier pile and lagging method requires significantly more dewatering. It will draw down the groundwater for a large area around the site whereas the secant method only requires dewatering the actual building area. Currently,the City has no idea how much dewatering will be required and can not assess the impact on City sewers and facilities. The excavation support system will not be trivial. It must be adequately designed and installed to support the 20-to 30-foot excavation without affecting the adjacent buildings,sidewalks,streets,and utilities. The Planning Board and the City should require an excavation support system and a dewatering plan to critique. 5. A further environmental concern includes the handling and transportation of the excavated material. The Geotechnical Report indicates that silt and clay exist from approximately 3 to 9 feet down to approximately 25 to 32 feet below the existing grade. This wet material needs to be sufficiently dried or transported with liners. No plan has been provided by the Applicant for on-site dewatering or protecting City streets and drainage systems from contamination of transported material. 6. The ApplicanYs Site Plan application indicated there would be 17,000 cubic yards (cy) of excavated material. Based upon the Revised Geotechnical Report it is likely the amount exceeds 18,000 cy. This could result in 1,700 to 2,000 trucks on Hamilton St. just due to the removal of this material. Has the Planning Board and City considered this in their assessment of the project and the impact on the community? The ApplicanYs Full Environmental Assessment Form ( see red highlighted on Figure 8) states there will be less than 1,000 tons of excavated material. This is incorrect; 17,000 cy exceeds 27,000 tons. This is a large impact environmentally. The SEQRA application is incorrect and the Planning Board has not vetted the project adequately. 13 ... . . . . Rclevant No,or Modcrate � Part I small to largc � � Question(s) impact impact may I ___ —__._ ma occur oceur a.The propoaed action�nay involve construction on land where depth to water table is 1:2d [� � Iess than 3 feeY. b.The proposed action may involve construckion oa slopes of 15%or greatec E2f ��� � r a'tl�e piuyused acliui�i mxy invulve eonsuvction ot�ladd�Vher2 bedrock is exposed,or E2a , ['� � genecally within 5 fcct of existiug ground surface_ ' d.The proposed action may invotve the excavation and removal of morE than 1,000 tons D2a 0 � of natural material. Figure 8—Partial Full Environmental Assessment Form 7. The Revised Geotechnical Report recommended drilling into the bedrock.The drilling will be along the entire perimeter of the site. This is significant.However,the does not mention possible concerns other than vibration effects. An aquifer is not mentioned in the report at all.How might the drilling affect the aquifer? This is not discussed. The springs in the area are not addressed. Historically,there was the Washington Spring at the Clarendon Hotel(now the site of the high school). The Grand Central Hotel(now the site of the Visitor's Center)had a drilled spring. The Columbia Hotel(between the Clarendon and Grand Central) might have had a spring also. How might the drilling affect these and other possible springs in the area? This needs further research. The point is we don't know what effect the significant amount of drilling on the site below the groundwater level will have on the water conditions in the area. Has this ever been addressed on any other building in the City? There have been reports of groundwater problems created on North Broadway from blasting.Shouldn't the City understand this site before proceeding? 8. The Revised Geotechnical report recommended: a. A pre-construction building condition survey of surrounding properties. 14 b. A vibration monitoring program should be included in the design of the excavation support system to include adjacent buildings,and streets. Vibratory methods of installing the excavation support should be avoided. c. Full-time inspection of the earthwork. These should be addressed by the Planning Board review. 9. The Planning Board should require the Applicant to submit their proposed dewatering method and excavation support system. A full assessment of the effects on the groundwater level should be included to indicate the possible impact on adjacent properties,streets,and utilities. Conclusions: The Planning Board should approach this project cautiously to not create significant problems for the City and the area of Broadway and Hamilton Street. The underground parking proposed for this building creates site and groundwater conditions not normally encountered in Saratoga Springs construction. There may be even more problems with the ApplicanYs submissions than what is stated here. However,with what has been presented, I believe there is sufficient information to say the SEQRA approval is faulty since it is based on incorrect and incomplete information and should be re-evaluated. My comments should be reviewed and vetted by the Planning Board. I look forward to your comments and a re-examination of the entire SEQRA application. Sincerely, David Biggs 268 Broadway Saratoga Springs,NY 15