We athe r Impac ts on Air Dispe r sion Pr e par e d for : SMC - PowerPoint PPT Presentation

We athe r Impac ts on Air Dispe r sion Pr e par e d for : SMC St. Mar ys Ce me nt Plant Community L iaison Committe e Me e ting 1 Pr e se nte d by: Winnie Song, M.Sc ., P.E ng. BCX E nvir onme ntal Consulting Mar c h 14, 2020

Ope ning 2 We a the r c o nditio ns ha ve sig nific a nt impa c ts o n a ir dispe rsio n. Wind dire c tio n is no t the o nly fa c to r. Air dispe rsio n is a lso impa c te d b y ho w sta b le the a tmo sphe re is (i.e . a tmo sphe ric sta b ility).

Outline 3 Atmo sphe ric Sta b ility a nd L a pse Ra te s Air Dispe rsio n unde r Diffe re nt We a the r Co nditio ns Air Dispe rsio n in the T o wn o f St. Ma rys Wha t will the Sta c k E xte nsio n Do fo r Air Dispe rsio n Co urte sy o f BCX Sta ff, BCX Pa int Nig ht, Oc to b e r 2019

Outline 4 Atmosphe r ic Stability and L apse Rate s Air Dispe rsio n unde r Diffe re nt We a the r Co nditio ns Air Dispe rsio n in the T o wn o f St. Ma rys Wha t will the Sta c k E xte nsio n Do fo r Air Dispe rsio n Co urte sy o f BCX Sta ff, BCX Pa int Nig ht, Oc to b e r 2019

Atmo sphe ric Sta b ility a nd L a pse Ra te s 5 T he drive r fo r a ir mo ve me nt is te mpe ra ture va ria nc e . Air te mpe ra ture va rie s with he ig ht. T his ve rtic a l te mpe ra ture va ria nc e dire c tly impa c t a ir sta b ility. T he ve rtic a l te mpe ra ture g ra die nts a re c a lle d “L a pse Ra te s”. L a pse ra te s a re use d to de sc rib e ho w sta b le the a tmo sphe re is (i.e . a tmo sphe ric sta b ility). L H T he two impo rta nt la pse ra te s a re Adiabatic L apse Rate (AL R) a nd E nvir onme ntal L apse Rate (E L R).

Adia b a tic L a pse Ra te (AL R) - Be nc hma rk 6 T e mpe r atur e Change s with He ight Adiabatic L apse Rate (AL R) is the ra te Dr y Adiabatic L apse Rate a t whic h the te mpe ra ture 1000 c ha ng e s/ de c re a se s with he ig ht in a n 900 e ve l (m) “ide a l” e nviro nme nt. 800 700 le vation Above Se e L T he AL R is a ppro xima te ly -1 ˚ C e ve ry 600 100m o r -10 ˚ C/ km. 500 -10 ˚ C/ km 400 T he ide a l e nviro nme nt a ssume s tha t 300 the a ir pa rtic le s a re “ isolate d ” fro m 200 E 100 the e nviro nme nt a nd wa rm o r c o o l 0 witho ut lo sing o r g a ining a ny e ne rg y. 5 10 15 20 25 30 T e mpe r atur e ( ˚ C)

Adia b a tic L a pse Ra te (AL R) - Be nc hma rk 7 T he c lo se st a na lo g y to de sc rib e AL R is a ho t a ir b a llo o n. T he a ir in the ho t a ir b a llo o n is “iso la te d”. Whe n the ho t a ir b a llo o n shrinks it do e s no t wo rk o n its surro unding s o r do e s it re q uire a ny wo rk to stre tc h. T he he a t tra nsfe r b e twe e n b a llo o n a nd the e nviro nme nt is slo w e no ug h to b e ig no re d.

E nviro nme nta l L a pse Ra te (E L R) 8 apse Rate (E L R) is the ra te E nvir onme ntal L a t whic h the te mpe ra ture c ha ng e s/ de c re a se s with he ig ht in a c tua l e nviro nme nt. T he E L R is influe nc e d b y pa tte rns o f he a ting , c o o ling a nd mixing a nd the pa st histo ry o f the a ir ma ss. T he diffe re nc e b e twe e n E L R a nd AL R de te rmine s ho w sta b le the a tmo sphe re is.

Outline 9 Atmo sphe ric Sta b ility a nd L a pse Ra te s Air Dispe r sion unde r Diffe r e nt We athe r Conditions Air Dispe rsio n in the T o wn o f St. Ma rys Wha t will the Sta c k E xte nsio n Do fo r Air Dispe rsio n Co urte sy o f BCX Sta ff, BCX Pa int Nig ht, Oc to b e r 2019

Air Dispe rsio n unde r Unsta b le Co nditio ns - 10 L o o ping Temperature Changes with Height 1000 900 800 Elevation Above See Level (m) 700 Amb ie nt a ir is c o o ling fa ste r 600 with he ig ht tha n 500 the “b a llo o n” 400 300 Dry Adiabatic Rate "Balloon" 200 o w wind  L Superadiabatic Lapse Rate 100 inte nsive ve rtic a l mixing "Unstable" 0 5 10 15 20 25 30 Temperature (˚C) Atmo sphe ric Sta b ility: Unsta b le , stro ng ve rtic a l mixing Wind spe e d: L o w T ime / We a the r o f o c c urre nc e : Sunny Da y Air Dispe rsio n Co nditio n: Go o d, do mina te d b y the rma lly induc e d turb ule nc e

Air Dispe rsio n unde r Sta b le / Ne utra l 11 Co nditio ns - Co ning Temperature Changes with Height 1000 Dry Adiabatic Rate 900 "Balloon" 800 Subadiabatic Lapse Rate Elevation Above See Level (m) "Stable/Neutral" 700 Amb ie nt a ir is Subadiabatic Lapse Rate c o o ling with 600 "Stable/Neutral" he ig ht a t simila r 500 ra te s a s the “b a llo o n” 400 300 200 Stro ng wind  100 little turb ule nc e 0 5 10 15 20 25 30 Temperature (˚C) Atmo sphe ric Sta b ility: Sta b le , OK ve rtic a l mixing Wind spe e d: Mo de ra te to stro ng T ime / We a the r o f o c c urre nc e : Clo udy da ys, da y/ nig ht tra nsitio ns Air Dispe rsio n Co nditio n: OK , do mina te d b y me c ha nic a lly induc e d turb ule nc e (winds)

Air Dispe rsio n unde r Sta b le / I nve rsio n 12 Co nditio ns - F a nning Temperature Changes with Height 1000 900 Elevation Above See Level (m) 800 700 Amb ie nt a ir te mpe ra ture inc re a se s 600 Dry Adiabatic Rate with he ig ht. Stro ng 500 "Balloon" ve rsio n re sults in ve ry Inversion Lapse Rate 400 sta b le a tmo sphe re . "Strongly Stable" 300 200 no turb ule nc e 100 0 5 10 15 20 25 30 Temperature (˚C) Atmo sphe ric sta b ility: Ve ry Sta b le , ve ry little mixing Wind spe e d: no t spe c ific T ime / we a the r o f o c c urre nc e : Cle a r nig ht the surfa c e c o o ls Air dispe rsio n c o nditio n: Suppre sse d turb ule nc e

Air Dispe rsio n unde r Sta b le / I nve rsio n 13 Co nditio ns – L o fting Temperature Changes with Height 1000 900 Elevation Above See Level (m) 800 T he a ir is wa rme r 700 b e lo w the inve rsio n la ye r, 600 whic h “a lo fts” the 500 plume . 400 300 200 Dry Adiabatic Rate "Balloon" 100 Inversion Layer below Stack 0 5 10 15 20 25 30 Temperature (˚C) Atmo sphe ric Sta b ility: Sta b le b e lo w the inve rsio n la ye r Wind spe e d: no t spe c ific T ime / we a the r o f o c c urre nc e : L a te a fte rno o n a nd e a rly unde r c le a r skie s Air dispe rsio n c o nditio n: F a vo ra b le fo r g ro und le ve l fo r ta ll sta c ks.

Air Dispe rsio n unde r Sta b le / I nve rsio n 14 Co nditio ns – Ca pping (F umig a tio n) Temperature Changes with Height 1000 900 800 Elevation Above See Level (m) T he a ir is wa rme r 700 a b o ve the 600 inve rsio n la ye r, 500 whic h “c a ps” the plume b e lo w. 400 300 Dry Adiabatic Rate "Balloon" 200 100 Inversion Layer Above Stack 0 5 10 15 20 25 30 Temperature (˚C) Atmo sphe ric sta b ility: Sta b le a b o ve the inve rsio n la ye r Wind spe e d: no t spe c ific T ime / we a the r o f o c c urre nc e : E a rly mo rning a fte r a sta b le nig ht Air dispe rsio n c o nditio n: Poor . Plume tra ppe d b y inve rsio n a b o ve sta c k he ig ht.

Diurna l Cyc le o f Surfa c e He a ting a nd Co o ling 15 1000 900 Mid Day Nig ht 800 Night Elevation Above See Level (m) 700 600 Morning 500 Mo rning 400 300 Ra dia tio n I nve rsio n 200 100 Mid-Da y 0 5 10 15 20 25 30 Temperature (˚C)

Outline 16 Atmo sphe ric Sta b ility a nd L a pse Ra te s Air Dispe rsio n unde r Diffe re nt We a the r Co nditio ns Air Dispe r sion in the T own of St. Mar ys Wha t will the Sta c k E xte nsio n Do fo r Air Dispe rsio n Co urte sy o f BCX Sta ff, BCX Pa int Nig ht, Oc to b e r 2019

Air Dispe rsio n in the T o wn o f St. Ma rys 17 - T he kiln sta c k is lo c a te d in a fo rme r q ua rry b e lo w g ra de . T he sta c k is sho rt re la tive to the e le va te d re c e pto rs in to wn. - T he rive r va lle y runs thro ug h to wn. - Ra dia tio n inve rsio ns a re inte nsifie d in the va lle y to Kiln Stac k re sult in ve ry sta g na nt a ir. Que e n Stre e t Are a - Sho rt sta c k + va lle y c lima te = Po o r a ir dispe rsio n.

Outline 18 Atmo sphe ric Sta b ility a nd L a pse Ra te s Air Dispe rsio n unde r Diffe re nt We a the r Co nditio ns Air Dispe rsio n in the T o wn o f St. Ma rys What will the Stac k E xte nsion Do for Air Dispe r sion Co urte sy o f BCX Sta ff, BCX Pa int Nig ht, Oc to b e r 2019

Wha t will the Sta c k E xte nsio n Do fo r Air Dispe rsio n unde r Go o d/ Ok Dispe rsio n Co nditio ns 19  T he sta c k e xte nsio n will e le va te the plume fro m the g ro und a nd SMC K iln pro vide mo re Sta c k vo lume fo r mixing E xisting a nd dilutio n. SMC K iln Sta c k with 30m E xte nsio n

Wha t will the Sta c k E xte nsio n Do fo r Air 20 Dispe rsio n unde r Po o r Dispe rsio n Co nditio ns  T he sta c k e xte nsio n will ra ise the plume SMC K iln (a po rtio n o f it if Sta c k no t a ll) a b o ve E xisting the inve rsio n la ye r to minimize fumig a tio n. SMC K iln Sta c k with 30m E xte nsio n