apr 2015 samuel unger - california state water resources control board · santa clara ri"

Samuel Unger Executive Officer

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX

75 Hawthorne Street San Francisco, CA 94105-3901

APR 3 0 2015

Los Angeles Regional Water Quality Control Board 320 We t 4th Street, Suite 200 Los Angeles, California 90013

Dear Mr. Unger:

I am providing this letter to clarify EPA's approval of the recent Los Angeles Regional Water Quality Control Board's amendments to site specific objectives (SSOs) for chloride in Reaches 4b, 5, and 6 of the Santa Clara River in Chapter 3 of the Region' s Basin Plan (Resolution No. R14-10). During our review of the amendment , we identified a minor change that we required to be made. Specifically, we indicated that the term "conditional" should be deleted from the amendments to Chapter 3 (Attachment A to Resolution No. R14-10). This term was found unnecessary in the context of the SSOs, given the implementation program in Chapter 7 (also adopted through Resolution No. R14-10).

We di cussed with and recommended to your staff that, to preserve the linkage to the implementation program in Chapter 7, minor, non-substantive changes be made to the implementation language for the SSOs in Chapter 3 such that the language would refer to "implementation provisions" for the SSOs instead of "conditions" for the SSOs. Your staff then provided a draft mark-up of the amendments to Chapter 3 based on our request (enclosed). We found the draft mark-up to be consistent with our request for the minor change and our subsequent discussions with your staff. Upon review of the draft mark-up, we issued our approval pursuant to Section 303(c) for the SSOs. In our approval letter, we did not mention the implementation language associated with the SSOs in Chapter 3, because we were not acting upon the implementation language in our action. However, we acknowledge that the Los Angeles Water Board has included implementation language for the SSOs in Chapter 3, which provides a linkage to the more detailed implementation program in Chapter 7. While we are not taking action on this language, we have no objection to it, and find it to be con istent with our understanding of how the SSOs will be implemented.

In conclusion, this letter is intended to clarify that our approval of the SSOs, dated April 28, 2015, was is ued with the understanding that the minor changes described above were made to the amendment .

Sincerely,

Enclo ure

cc: Rik Ra mussen

f'rinled on Recvcled Paper

Resolution No. R4-2014-010

Attachment A to Resolution No. R4-2014-010

Basin Plan Amendment Incorporating an Averaging Period for Chloride Water Quality Objectives in Three Reaches and New C8atliti81Utl Site Specific Objectives

for Chloride in Two Reaches of the Upper Santa Clara River

The following language wi ll be modified in Chapter 3, Water Quality Objectives of the Basin Plan, under "Mineral Quality" 1:

Revise Table 3-10 "Water Quality Objectives for Selected Constituents in Inland Surface Waters" as follows:

Add footnote "m" under column labeled "Chloride (mg/L)" for the following rows:

Between Bouquet Canyon Road Bridge and West Pier Highway 99 Between West Pier Highway 99 and Blue Cut gaging station Between Blue Cut gaging station and Piru Creek

Add description of footnote "m" at the bottom of the table

m. These objectives apply as a 3-month rolling average. The 3-month averaging period for these objectives was established though a Basin Plan amendment adopted by the Regional Board on October 9, 2014 (Resolution No. R14-0xx) and went into effect on {insert date}.

1 Note that table numbering is according to the numbering in the Non-Regulatory Amendment to the Basin Plan to Administratively Update Chapter 3: "Water Quality Objectives" by Jncorporating Previously Adopted Amendments and Updated Tables (Resolution No. R 13-003, adopted by the Regional Board on May 2, 20 13).

Resolution No. R4-20 14-0 I 0


Basin Plan Amendment Incorporating an Averaging Period for Chloride Water Quality Objectives in Three Reaches and New Cetulitieoal Site Specific Objectives


Revi se Table 3-1 Oa and associated text as follows:

Table 3-lOa. Coodititntal Site Specific Objectives for Chloride in Upper Santa Clara River Watershed Surface Waters

WATERSHED/STREAM REACH REACH

Chloride (mg!L) NUMBER

U(!per· Santa Clara River Watershed:

Between Bouquet Canyon Road Bridge §. 150 and West Pier Highway 99 (-h!-3-month ro ll ing average) Between West Pier Highwax 99 and the 2 150 Valencia WRP o utfall 00 1 (3-month rollina averaae) Be~'lc'l'een West Pier 1-ligi'lwa:;· 99 emEl Bll:le -84 G!:it gaging stutioH f'l') ~,.,,.J-, n '~ • ,. ,\

- .. . ~ ...... -~b-.

Bet•.veeA: Bhfe G1:H gaging station aHEI 117/1301100 coHf!l:leA:ee of PiFH Greel~ {'l .~ ,\b

~~ ' ·' " -' ' •<" "' '"' ' "'IS'"'

a. The conditional site speeiiic objective of 130 msxfL applies only ifthe following conditions and implementation requirements are m et: I. Water supply chloFiEie concentfations measured in Gastaic Lake are> 80

mglh 2. The Santa Glarita Valley Sanitation District (SGVSD) shall proviEie

s!:ipplemental watef to sa lt sensitive agricu ltmall:lses that are irrigated with surface v~ater during periods when Ri}ach 4B (between Blue Gut gaging station anEI confluence of Pint Greek) surface watef e><eeeds 117 mwL.

3. By May 4, 201 0. the I 0 year cumulative net chloride loading abo·~e 117 mg/L (GNGil l 7t to Reach 4 B of the Santa Clara RiYer (SGR), calculated annHally, from the SGVSD Water Reclamation Plants (WRPs) shall be zero or less.

+-GNGfm-=-Gt(AheH 117)~{-Helew-i-l-+7~(E~;port Ev.'S)

Where: GJ.(Alaoel17)

Q(Bele .. 11 7)

[WRP Cl Load\1Reaeh 4B Cl bond~] * [Ri:lach qB Cl bona-++'~-"}

- (WRP Cl Load+JReaell 'IB Cl Loa6~] *[Reach 1B Cl boad--!+l4 }

g(!:Hpen E" "•l Cl bead ReFRoveEI ey Eli:!I"RetiOA Wells

+-\VRP Cl Load is determifled as the n1onthly average-t:;hloride (CI)-ooneentration mul~ tHe-monthly average-fle-w-measured at theJ.l.al.efleia \!/RP.

;1-ReadJ 4B Cl Load is detel'fltifled-as-the monthly average Cl eoncentmtion at SCVSD Reeei•1iag Water Station Rr multiplieEI B)" the JROAthly R"lerage flow tfleRsurecl at USGS Ga~:~gi ng StRtion Ill 09009 (Las Brisas Bridge).

2

Resolutio n No. R4-20 14-0 I 0


Basin Plan Amendment Incorporating an Averaging Period for Chloride Water Quality Objectives in Three Reaches and New C8B~iti8Ral Site Specific Objectives


'>-Reaeh 48 Cl Load"+~-+ AleBAS the oalettlated Clload to Reaeh 48 .,.,·heR mOilthly 8\'erage Cl eoneentration iA Reaeh 4B is above 117 ll'lg/L.

4 Reaeh 48 Cl Load.:.m: means the oale1:1l8ted Clload to Reaeh 'IB ·n·heA montlll)' 8\'erage Cl eoHeentration in Reaeh 4 B is below or equal to 117 mg/L.

4. The chief engineer of the SCVSD signs under penalty of perjury and submits to the Regional Board a letter documenting the fulfillment of conditions 1, 2. ftf'l4+.

b. The averaging period for the critical condition SSO of 130 mg/L may be reconsidered based on results of chloride trend monitoring after the alternative \Vater resources management (AWRM) system·is applied.

Implementation Provisions for site specific objectjyes

Thejmplementation provisions for the @8tu~itienal site specific objectives for chloride in the surface water between Bouquet Canyon Road eftridge and West Pier Highway 99, and between West Pier Highway 99 and the Valencia WRP outfall 00 I and Blue Cut gaging station. and between Blue Gut gaging station and cont1uence of Piru Creel< shall Bf3~ l ) aA8 !HiJ!IelPS@d e the enistiAg v.!ltet· E!lll!l li t) E~Sjestives iA Taele 3 8 I Q 8Ml ) \': isleA

require that SCVSD to operate tlow wei!!hting projects chloride load reductions and/or chloride C1tport projects tua iH 8f3e:l'alien a~ d~e ~CVSD according to the implementation section in Table 7.,.: 6-) of Chapter 7.

Remove Table 3-13.a and associated text as fo llows:

Table 3 13a. Cenclitienal Site Specific Objectives fer Selected Censtituents in Regienal Creunclwaters

DWR BASIN Chlericle Emg,£1:,~ Basin Ne. ¥enturo Ceastal

bower area east of: Pi ru GFeel~+ ~

4-4 (Fe lling 12 mentA fWeFao:e)

4-4-:(}+ Eastern Santo Claro

Santa Clara Bouquet & San Francisquito Canyons l§O (Foiling P month average)

l §0 Erolling 12 r . ''"II. ••• ,\ ~"~'"'~ ""~,

3

Resolution No. R4-20 14-010


Basin Plan Amendment Incorporating an Averaging Period for Chloride Water Quality Objectives in Three Reaches and New Cstulitisnal Site Specific Objectives


1. This objective only applies to the San Pedro formation. EJ<isting objective of 200 mg/L applies to shallow allu'tium layer above San Pedro fom'lation.

The conditional site specific objectives for chloride in the groundwater i11 Santa Clara Bouquet & San francisquito Canyons, Castaic valley, and the lower area east ofPiru Creek (San Pedro Formation) shall apply and supersede the eJ<isting regional groundwater quality objectives only when cl:lloride load reductions and/or chloride eJ<port projects are in operation b)' the SCVSD according to the implementation section in Table 7.6 1 ofChapter7.

4

·I

Attachment B to Resolution No. R4-2014-010

Resolution No. R4-2014-010 Page I

Revision of the TMDL for Chloride in the Upper Santa Clara Riv~r

Revised by the California Regional Water Quality Control Board, Los Angeles Region on October 9, 20 14.

Amendments

Table of Contents

Chapter 7. Total Maximum Daily Loads (TMDLs) 7-6 Upper Santa Clara River Chloride TMDL

List of Figures, Tables, and Inserts Chapter 7. Total Maximum Daily Loads (TMDLs) Tables

7-6.1 . Upper Santa Clara River Chloride TMDL: Elements (Revised) 7-6.2. Upper Santa Clara River Chloride TMDL: Implementation Schedule (Revised)

Chapter 7. Total Maximum Daily Loads (TMDLs) Upper Santa Clara River TMDL

This TMDL was adopted by: The Regional Water Quali ty Control Board on October 24, 2002. This TMDL was remanded by: The State Water Resources Control Board on February 19, 2003 This TMDL was adopted by: The Regional Water Quality Control Board on July I 0, 2003.

This TMDL was revised and adopted by: The Regional Water Quality Control Board on May 6, 2004.

This TMDL was approved by: The State Water Resource Control Board on July 22, 2004 The Office of Administrative Law on November 15, 2004 The U.S. Environmental Protection Agency on April 28, 2005

Thi s TMDL was revised and adopted by: The Regional Water Qual ity Control Board on August 3, 2006.

Th is TMDL revision was approved by: The State Water Resource Control Board on May 22, 2007. The Office of Administrative Law on July 3, 2007.

This TMDL was revised and adopted by: T he Regional Water Qual ity Control Board on December 11 , 2008.

This TMDL revision was approved by: T he State Water Resource Control Board on October 20, 2009. The Office of Administrati ve Law on January 26, 2010. The U.S. Environmental Protection Agency on Apri l 6, 201 0.

This TMDL was revised and adopted bv: The Regional Water Qualitv Control Board on [insert date].

This TMDL revision was approved bv: The State Water Resource Control Board on [insert date]. The Office of Administrative Law on [insert date]. The U.S. Environmental Protection Agency on [insett dakl.

Resolution No. R4-201 4-010 Page 2

Resolution No. R4-2014-010 Page 2

Table 7-6.1 Upper Santa Clara River Chloride TMDL: Elements

Element Table 7 6.1. Upper Santu Clara Ri'\·er Chloride TMDL: Elements

Santa Clara Ri"<•eF ChlerideRegulatory Pro,isions

Problem Elevated chloride concentrations are causing impairmeAts exceedances of the Statement water quality obj ecti ve~ in Reach 5 (EPA JOJ(d) list Reach 7) and Reach 6 tEPA

303(d) list Reach 8) of the:.: Santa Clara River (SCR). These reaches are-have been on the 1998 BAd 2002 Clean Water Act (CWA) section 303(d) lists of impaired water bodies as impaired due to chloride since 1998. -The objectives for these reaches were set to protect all beneficial uses; the agricultural supply beneficial uses ha~-ve been determined to be the most sensitive, aAEI Ret CI:IFFCA:tiy at:taiAeEI at the dewAstream et~EI ef Reach 5 (EPA 303(d) list Reach 7) aAEI Reach 6 (EPA 303(EI) list Reach 8) _in the Upper Santa Clara River (USCR). Irrigation of salt sensitive crops such as avocados, strawberries, and nursery crops with water containing elevated levels of chloride results in reduced crop yields. Chloride levels in groundwater are also rising in Piru Basin. which uAEieFiyiAg underlies the reach downstream of Reach 5 ~:v ..:!_.~ <~· ,5 .

Numeric For Reach 4B and Reach 5 downstream of the Valencia Water Reclamation Plant Target (WRP) outfa ll 001. the numeric target for chloride in the surface water is 1 00 (Jnterpretati mg/L. measured as a 3-month ro lling average, which is reguired to atta in the on of the water guali ty objective and protect the ae-ricultural supplv beneficial use. numeric water quality For Reach 6 and Reach 5 upstream ofthe Valencia WRP outfal l 001. the objective, numeric target for chloride in the surface water is eguivalent to @8"8i~i8fUtl site used to sgecific objectives (SSOs) o' 1 :( 11'\. 'L_ measured<.. <.1 3-J 1_1 _:_ol ing ~I' ~ <lb-.. calculate the contine-ent upon the Santa Clarita Vallev Sanitation District's (SCVSD} hHHI operation offlow-wei!!hting gro jects. As described in the waste load allocation allocations) (WLA) section of thi s table. the Valencia WRP is assigned a variable WLA less

than 100 mg/L as a 3-month rolling average. which allows the Saugus WRP to discharge UQ to 150 mg/L as a 3-month rolling average. whi le still meeting the numeric target of I 00 mg/L as a three-month rolling average immediately downstream of the Valencia WRP outfall 001.

}.J~;~merie Hn'gets are eEJtti,.,aleAt le eet=tElitieAal site Sj3eeifie ebjeeti~· es ~8SGs) U~at

ere eased en teehAieal shtdies Fegan:liAg ei11eriee le•,•els 'Nhie l~ pretest salt seAsiti,-e erOf3S aRE! eneaAgereEI aRe tlueateAee speeies. chleriEie seuree ideAtificatieA, aAEI the megt~ituEie ef assimi!ati•,•e capaeity in the Uf3f3eF reaches ef the SaAta Glara Ri'f•er aAEII:IAderlyiAg gFEH:lAEiwa~er easiA. +he +M9b Sf3eeial shta~-. biterat1:1re R:e¥ie·~,- E¥ehtatien. she,.•s that the mese seHsiti•ve eeAefieiel ~:~ses can ee supf3et1eEI •.vith ro ll ing a•reragiAg periees as shown in the taeles ~

I. GoAEiit:ieAal Smface :water SSGs

E lement

Resolution No. R4-20 14-0 I 0 Page 2

Taele 7 6.1. U pf3eF 8aBta Clat·a RiYer Chlaride T:'\IDL: ElemeBts

Santa Clara Riv•er CJtlerideRegulaton Provisions

+l=le eeAEiitieAal S8Gs f:eF ehleriEie iA the SHFfaee wat:er e~ Reaches 4 B, §, aBEl 6 sl~all aJ3J3I~· aAEI SHf.lCrseae the e~risting wateF €fHality eejeeti•f•es of I 90 FAgtb eAI;· •n-fieB efileFide lead FeaHetieRs aAatOF ehleFiEie C*f.lOFI f3Fejeets are iA Of3eratieH B:Y the SCVSD aceerding to the implementation seetion iA +able 7 6.1. ConditioRal s,S,urface water qual it\· &sGs-ob jectives for Reaches 4B, 5, and 6 of the Santa Clara River are .J-i5tee.-as fo llows:

Reach CeBditieBal Rolling SSGSurface Water Averaging Oualitv Objective Period

for Chloride (mg/L)

6 1 50~ -l-11-month 5 ( UJ2Stream of Valencia 150* 3-month WRP outfall 001}

5 (downstream of Valencia +WIOO .J-2.}-month WRP outfall 00 I} 4B +-lflOO 3-month 4B Critical CeHditioAs ~il ~ ITIOAtA6

*The 88M8i!i~u;utl SSO for chloride in the surface water of Reach 6 and Reach 5 UJ2Stream of the Valencia WRP outfall 001 shall aJmlx and su12ersede the existing water guali tx objectives of 100 mg/L as a 3-month rolling average onlv when flow weighting grojects are in o12eration h\ the ~CVSD accordinu to the implementation section below. As described in the WLA section of this table. the Valencia WRP is assigned a variable WLA less than 100 mg/L as a 3-month rolling average. which allows the Saugus WRP to discharge UQ to 150 mg[L as a 3-month rolling avera2:e. while still meeting the numeric target of I 00 mg/L as a 3-month rolling average immediatelx dovmstream of the Valencia WRP outfall 001. The interim milestones listed in the imQiementation schedule in Table 7-6.2 ensure that the faci li ties needed to attain flow-weighted WLAs are constructed in time for the Saugus and Valencia WRPs to atta in tht final WLAs.

a. +he eoneitiot~al SSG fer el~leFiae iA: R:eaeh 4 B tmEieF eritieal eoA:EiitioR shall apply only if the fol lowing eoAditioAs aRd imf.lleFAeAtation re€fuiFemems are met:

1 U T. .I n l.l ',.l .. • rl . 0 . . 1 - ' · ' .. ~•v• "'~!-'~' ~· '~

Element


Table 7 6.1. UJtpeF Santa Clara RiHF Chlaride TMDL: ElemeHtG

Sttnta Chtra Rher Chh~FideReguJaton Pro,· is ions

80 mgtb. 2. ::n~e SaHta Glari~a ~'aile;< SaAi~atieA -9i:striet (SG¥891 sh£tll f.lFO'viEle

suf!p l emet~tal '~'•'ater ie self. seHsiti'l•e agrieu lt~:~Fal ~tses thaf are irrigates 'Nith s~:~rface '<Vater during periods wheA Reach 4 B sw-faee water e~<:ceeEls II+ tfl§1b.

3. By Ma~· 4, ~g;w, tlie I g ]'CEll' 61:11flt!lati'I'C Aet ehleriEle leaEi iAg ase>re ll+ mgib (GNGI.wl to Reach 4B efthe SGR:, ealettla~eel aAAt!all~·, from the SGVSD Water R:eelamatioA PlaAts (WRPs) shall be zero or k5s:-

-i-GNGJ.+++~~_gf.&hwr-+l-+t_g(E!Ifl81t Ews-j

Where: bt(Aee'•c II 7) [WR.0 Gl boael+tReach 4B Gl LoaEI~] * [Reach 4B Gl bead-..-..~-~:i31 bt(Belew 117) f.WI~P Gl Lood+tReach 4B Gl Lead~] * [ReHch 4B Gl ~4t

bt(E!IfleH EWsJ Gl bead RemO'<'Cd sy e~<:traetieA Wells +-};.tRP Gl beael is Eletem'liAeEI as the meAthly £P~<'erage Gl eeAeeBtFatieA m~:~ltif!lieelsy the tl'leAthly· average flo,,,. measuFeEI at the ValeAcia WRl2:-

;!-R:each 'I B Gl boaEI is EleteFmiHeEi as the moAtl=il~· a>rerage Gl eoAeeAtratiot~ at SGV~)-9 Receiving WateF StatieA RF t'fH:tltiJ3Iieel b~· the moAthl;< average flow meas~:~reEi at USGS Gauging StatioA lll G99GG (bas Brisas Brielge~.

;...Reach 'I B Gl Loae1'4++ meal'!s the ealeulateel Glloael to Reach 4 B when monthly average Gl concentration iA Reach 4B is above 11+ mgfb

4 Reach 4 B Gl boa~ meaRs tl=<e eelettlatea Gl Ieee to !~each 4 B when monthly a>rerage Gl coAcentratioA in Reach 4B is belov.• or eq~:~al to II+ rng/6.

4. +he chief eAgineer ef:the SG¥SQ sigHs ~:~REier J:'CAalt;< of:J3e~tu·y enel submits te the :bos A:t'lge les R:egieAal \Vate:r Q~:~ality Gontro l BoarEI (Regional Board) a letter EiocumeAting the fulfillment of: conditions I, 2, ana "> :r.

e. +he e"·ereging periea fer the eritieal coAElitien SSG ma;< ee recoAsielereE:! saseel OR resl:!lts or chloriele trenEI ffiOAitering aft:eF the eonEiitieAal WbAs of this +MQb are iFAJ3Iemented.

Element

Source Analysis

Linkage Analysis

Resolution No. R4-20 I 4-0 I 0 Page 6

Table 7 6.1. l'pper S&ota Cl&ra Ri' er Chleriae TMDL: ElefHents

Soata Clara Ri~·er ChlerideRegulaton Provisions

2. Conditional SSOs for GrouAdwater

CoHEiitioBal grotlnElwaler SSOs are listeEI as t'ollo>v,•s:

Creundwater Cenditien&l Rolling AveragiAg BttsHt Groundwater Period

880 for Ghleride En1gfbj

Santa Clara ~ l2 month Bouquet & San Francisquito Canyons Castaic Valley ~ 12 month

Lower areo east of ~ 12 month Pir1::1 Creelt tt

" =Fhis oejecti¥e onl)' aj3j3lies to Hle San Pedro formation. Blt:istiAg o~ecti¥e of 200 mg!L applies to shallow allu·tium layer above San Pedro t'onnation.

+fie cenEiitioAal SSOs fer c l~l oriEie in tfle gro~::~nelo,.,·ater in Santa Clara Bouquet & San 11rancisquito CanyoAs, Castaic Valley anEI the lower area east of' Pirtl CreeiE ESan Peelro Formationjsflall appiJ' anEI SUj3ersede t~e elt:istiBg grouBEl•n•ater quality o~eeti•,•es on I)' when cfll oriele loael reEitJctions aneUor eh loriele eltport projects are in operation by the SCVSD ciccoreling to the implementation section in =Fable 'f. 6.t.

The principal source of chloride into Reaches 5 and 6 of the Santa Clara River is discharges from the Saugus WRP and Valencia WRP, which are estimated to contribute 70% of the chloride load in Reaches 5 and 6. These sources of chloride accumulate and degrade groundwater in the lower area east of Piru Creek in the basin.

A groundwater-surface water interaction (GSWI) model was developed to assess the linkage between chloride sources and in-stream water quality and to quantify the assimilative capacity of Reaches 4A, 4B, 5, and 6 and the groundwater basins underlying those reaches. -GSWl was then used to predict the effects of WRP discharges on chloride load ing to surface water and groundwater under a variety

Element

Waste Load Allocations (for point sources)

.


Tallie 7 6.1. bf.lper SaBta Clat·a Rint· Ckleride T"\IDL: EleBtents

Sttnta (;lara l~i·~·er (;klerideRegulatorv Pro\'isions

of future hydrology, land use, and water use assumptions~ including future discharges from the Newhall Ranch WRP,_ in order to determine appropriate wasteload allocations (WLAs) and load allocations (LAs) and eva luate the effect of using WLAs exgressed as a flow-weighted average between the Saugus and Valencia WRPs.

The linkage analysis demonstrates that beneficial uses can be protected through a combination of SSOs for sutface water ~md groundwater and reduction of chloride levels from the Valencia WRP effiuent through advanced treatment.

~rhe conElitional WbAs fer el=lleriEie fer all ~oint sourees shall a13f3l~' onl~' when ch:toriEie load reEiuctioHs aBEIIor chloride e~<f30Ft 13r~eets are iA 013eration ey the SGVS9 aceorEi ing to the im13lemeAtatioA seetioA iA =Faele + 6. t. u=these coAditions are not met, WLAs shall be bases on existing water quality oejectives for ch loride of 100 mg/L.

ConElit ional WLAs for chloride for dbeharges to Reach 4 B by the Saugus ana ~ialeneiu WR,lls are as folle'>1c'5:

Reaeft CtmeentFatien based Cenditienal WLA fer Cklel'ide

(mgfL~

4B II+ E~ ITienth ,<\veFage1, 230 E9aily MaJdmum)

4B Critical +-3-{}6 E~ ITI8A£h Average6t; CoAEii~ieAs 2~0 (9ail~· Mt:ntiffitttfl1

a. +he CenditioHal \¥6z6t tmder critical cenditions sl:!all aj3j3l ~' SA ~ ~' if the ffi!le•v•'ing ceHditieHs ~md im13 leffieAta~ioA FeE}HiremeHts are H~et :

1. \Vater SUf3ply ehleride ceneeAtrations ffieasHred in Castaic Lake are > 80 mgiL.

2. SC:\L£:9 SAall pre~·iae Sl:lj3J3Iemenfal \'c'ater to salt SeAsiti•te HgFieultural uses tl~at aFe irrigates ""'iti:l stn=faee •NateF d~:~FiAg 13erieas when Reach 4B surface water e)<eeeds I 17 mg/L.

26. B~· MH)'' 4, 202Q, tl'le I Q year CUffittlati•t'e net ehloriae loadiRg aee•,<e l 17 ITig/L fC~~Cl++:71-+ to R:each 4B ef ~l'le SGR:, ea letllal:ea aHAually.

Element

Resolution No. R4-2014-0 IO Page 8

Tttble 7 6.1. Upper Ssots Clttra Ri..-er Chlef'ifle TMDL: Elements

Sants {;lara Ri'l·er ChlerideRegulaton Provisions

from the Saugus end Valencia WRPs shall be zero or less.

i-GNGJ.-1+1-=-Gl(Ahfffl!-1-i-7-)--GJ.fBelffi.l-+l-f.j-GJ.f!;~porl l-Ows}

Where:

GJ.(AeeYe 117) fnq~p n Cl Load"'/Reach 48 Cl Load;;] >j< rReach 4B Cl bead-:.Hit

bt(Rela· .. II 7) PliR-P rr'- Cl Load-1/Reach 4B Cl Load~] ~ [Reach 4B Cl bead.=l-1/}

Gt(Elrflert E\lls) - Cl Load Removed by Extraction Wells

+-wR:.Q Cl Load IS deterrniHed as the rnoFHI1ly cP,.erage Cl concentration multiplied by the monthly average flo·N measured at the ValeHcia WR.P. 1--Reaeh 4B Cl Loael IS el:etermine€1 as the IHOI~th l ~• e¥erage Cl eeHceBtration-tH SC:V89 Rece iving l,!fater S~Et~ien RF mttHiplied ey the A'IOHthly a'"erage fle .. v measured at USGS Gauging Station 11 I 09000 (Las 8risas 8rielge). :;..Reach 4B Cl Loea::>-~-~-=~ tfleans the calculates Cl loaEI to J~eaeh 48 'Nhen month I~· average Cl cencentfatien i11 Reach 4B IS aeo¥e ll+ mgfb-: 4 Reach 4B Cl boaa4=!-l+ means the calcl:llateEI Cl load lo Reach 4B when A'IOI'ltl=lly average Cl concentration 111 Reach 48 IS below or equal to 117 mglb.

11. +he ch ief: e1~gineer of the S('YS9 sigBs ~mEier peAalt~· of J3e~jm·y and sui31Hits to the Regiona l Boarel a letier documenting the fulfi llment of eoneli~i ons l , 2, anel3.

b. +he a\•ereging peri eEl for n'le critical 6onai~io11 \"tt/bl'\ n~ay ee FecEmsidered ba!'leel en results o~ cl:lloriEie tfenel moAitoring after the conditionnl WLAs of this +MDL are irnplernentea.

• Conditional WLAs for Saugus and Valencia WRPs

The final conditional WLAs for chloride for the Sau2:us and Valencia WRPs shall am2lv onl y when flow-weighting grojects are in ogeration by the SCVSD according to the implcml.!ntation section below. lfthese flow-weighting conditions are not mel, WLAs for each Qlant shall be based on water gualitv

Element

Resolution No. R4-20 14-0IO Page 8

Table 7 6.1. Upper Santa Clara Rher Chloride TMDL: ElemeBts

8antft (;lant Ri•.-er (;hlorideRegulatorv Provisions

objectives for chloride of I 00 mg/L as a 3-month rollin!r average.

Discharges to Reaches 5 aAd 6 by the The Saugus and Valencia WRPs will have final concentration-based und muss based conditional WLAs for chloride l:lase€1-ex12ressed as a tlow-weif!hted average of the combined effluent of the Saugus and Valencia WRPs eit-€en&iti:eflal SSOs as fo llows:

WRP Concentration-based Ma:ss based Conditional WLA for Chloride Conditional :WbA fet'

(mg/L) Chlot'ide

fllOUnf:lsfdayj Saugus 150 (H}-month Rolling Average) Q :iq -(.) l:b*8 "4 9e:ngfl ) mg, . .,

,-230 (Dai ly Maximum) ( l2J. month Average)

Valencia C J.-~1 L,__lmp. c~t Q&e&igtl * l 5 (.) l (.)(.) ..J:-5..G-(H}-month Rolling Average) mg/L*8.3'1 AF-R-G

,-230 (Daily Maximum) E I ;t~ mentA Average)

Where: 3

[QsAu,mJ100 - CsAu,mJ + 100] CvAL,3mo.av = 1/3 I QVAL,mi

mi=l

QsAu,mi= Saugus WRP monthlv effluent flow in million gallons per day (MGD) QvAL,mi= Valencia WRP monthlv effluent flow in l'vlGD CsAu,mi= Saugus WRP monthly effluent chloride level in mg/L CvAL,m;= Valencia WRP monthly effluent chloride level in mg/L

QsAu,miand QvAL,mi shall not exceed the design tlO\v during dry-weather 12eriods

l,Vhere Q~ is Hie Elesign caf.}aei~:;' e~ WR:Ps iA t!Aits ef rnillien galleHs 13er Ela:;· ~MG9), AFRG is tl:ie el1 leriEle mass loading adjustment factor for operation of reverse esmesis (RO) faci lities, where:

If RO faeili~ies are operated at "' 59% Capacity Factor17 iA preceding 12 rnenths

AFOO--=-tt

Element

Resolution No. R4-2014-0 IO Page 8

Table 7 (d. Upper Santa Clara Ri-YeF Chleritle T:\IDL: Elements

Santa Giant Ri'<•er Ghi&AtleRegulatorv Provisions

lf RO facilities are operated at< 50% Capacity Factore in preceding 12 months

Moo (50% Capacity Factor %RO Capacity) * Chf.orideLoatlRCY

e-capaci~-tor is based o~fvlGD of recycled v1uter treatee with RO, 90% ofthe time. &-If eperatfet:t of RO facilities at <50% rat eEl CaJ98C ity IS the res\:! It of eeHditiens that are eHtsiEie tlie COHtrol of SC:VSf>, then under the discretion ofthe Executive Officer of the Regional Board. the AFw-rn-ay be set to 0. e-chloride loaEi red1:1ction is l=laseEi on operation of a RO treatment plant treating 3 MOD of reeycleEi ,:vater ·nith chloride concentration of 50 mg/L + Water Sup13 l~, ChloFiEie. Asstm~eapaeit~· factor of 90% and RO ffieH1i=lrane ehloriEie rejection rate of 95%. Determ.inati on of chloriEie loaEi based on the folio\~

ChloT'ideLoadRO ""90% )( KQRO )( CJV/I.P )( 8.34)>< r ] >< eODayl'i&onth) \Vhere: Qw 3 MOD efrecycleEI 'f"''ater treateEi '~'•'itl, RO GWIW GhloriEie eoneeHtratioA ll'l wateF supply .j. 50 rng,IL r % Re.,·eFse Osmesis e!:lleriEie rejectioA (95% or 0.95) 8.34 Conversion factor (ppEI/(mg/L*MGf)))

+l:le final \VL,6,s for +9S and s~:~lfate are CEjttal to e~tistit~g SHffaee water anEI grol:lBEi'<'f'atef EjUalitJ· osjec!:t'.'CS fBr +:98 anEI St:tlfate iR +abies~ 8 aHEl 3 I 0 eftl:le BasiH :PlaH. +he R:egior~al BoaFEI n'la~· I'C'I'ise the fiAal Wl:.A:s 13aseEi oR revie'lv of trenEl monitoring data as Eietailed in t!:le monitoring section of this BasiH Plait amenEiment. • WLAs for other NPDES discharges

Gther H'linof NP9BS Elischarges Eas ElefiHeEI iH +al=lle 4 l of the BasiA Plan) receive conditional WLAs. The conEiitioHal WLA for these point sources is as fullo'ws:

Reaeh GeneentFBtien based Cenditienal WLA feF

Ghleriae (mg/b)

6 150 El ~ lflonth A:'?eHrge), ~30 (9ai ly Mm~: i tTIHm)

Element

Load A llocation (for non point sources)

Tahle 7 6.1.

Resolution No. R4-2014-0IO Page II

tfiper Santa Clara Rinr Chlaride TMDL: Elements

Santa Clat·a Ri,.·er ChlerideRegulaton Pro,·isioo~

:S l §f) E1 ~ m:et~th A\·erage1, 239 (Daily Maximum)

4B II+ (3 tflenEI9 A:¥erage), 239 (Dail~· Ma~~imum)

Other ~NPDES discharges (as defined in Table 4 I of the Basin Plan) receive WLAs equal to 1 00 mg/L as a 3-month rolling average. The Regional Boars may eensiEier assigniAg eoneitieAal \VbAs to otl=ler major elisc19argers baseel en aA aAal~·sis of the elewHstreatfl iAerease in net el91eriee leasing to surface vt'ater and grouneviater as a result of implementation of conditional W·LAs. The source analysis indicates nonpoint sources are not a major source of chloride. The conditional LAs for these nonpeffit-soorees are as below:

Concentration based Rea$ CoHditioHal bA for ChloriEie

r. II \ ,' " 6 ' ~.

6 1 §Q (1 ~ meHth A,.·erage). ~39 (Daily Maximum)

:S I §Q 02 montH: ,A.•,•erage), 239 (Daily Ma>timum)

4B II+ (3 moHth ,6, ,,· erage~.

239 (Daily Ma><:imum)

:ri:!e co11ditional bAs shal l apply only '<'~'Hen ei:!:loriEie loaEI reEiuctions anEI,lor el:l loriEie e><:pert projects are in operat ion by the SCV8D a:eeording to ti:!e implementatio11 seetion in Table 7 6.1. lfthese conditions are not met, LAs are based on existing water quality objectives of 100 mg/L as a 3-month rol ling average.

Implementation Refer to Table 7-6.2.

Resolution No. R4-20 14-01 0 Page 11

Im{2lementation of_ Ul2J2er Santa Clara River ~miitifmt~~ Site Sf2.ecifl.c Objectives and IYLAs for Chloride

lfl aeeerEiaBee wi£1~ R:egieAal BearEI reseiHtieA 91- GG;t, the RegieAal BoaFEi ana stal~ei'!eleel'S have Elevelof3eEl aA ifltegra{ea wffiemflee f3 laA to aEIEil'ess el'lloriae il'fl{'}airl'fl eAtS !:lAS f3FOteet ael'lefie ial ttses ef Slifffiee 'Naters ana gFeHRElwaterl3-as-ifls ~l AEieflj'iflg R::eaehes 4B, §, aAEI6 e~ti:le SaAta Glal'a River. - :r~:~e 13laH iA'<'Oh'es: l j R:eEitteiRg ehleriae leaas aHEifer iHeFeasiflg efl.l.el'iEie e~~J3orts from the l:JSGR: watersl1ea tl'lre~::~gl:! imf3lemeAtatieA-Bf aE!•,·aAeeEI tl'eatt'l'leBt 0~9j e~ a J'Oft:ieR e~ tfie effiHeH!: fmm the ¥alefleia WR:P. +he aElvat'leeE! treateEI efth:tent •Nil! ee ElisehaFgeEI into R:eaefi 4B OF alel'lEieEl 'f'l·itl'l e~ttFaeteEI gF8 HHEI'l11'Hter from the Pil't! BasiA ttnaerl~'iHg Reaeh 4B aREI Elisel'largeEl in:te Re!i€h 4"~£. The resultant brifle from the aavuneed treatment f31'06eSS wi JJ ae EliSf30Sed iRa legal and e!~J' SOtll'lE!I'l'IUHAer. ;tj ll'l'lptemeAtiHg the eoREiitioAul SS9s fef ehloFiEie in Sttrfuee 'Naters aAEI t!AElerlyiAg grot!Hth'<'ater aasiHS of:the USGR watersl:!ed proviEied iA Ghapter 3.

The watefsl:!eElehloride redt1etion f3laA: !!8t~8i~ie1utl SSOs and WLAs fbr ~l'l.Jorj~_wi ll be implemented through effll!~n t and rece i y!_11_g_~vater limits. monitoring reguirement and other conditions in NPDES permits fo r the Valencia and Saugus WRP~ anEI a ne·,~• NPDES permit for discharge iAto Re!wh 4A. The @€H~diti!maJ SSOs for chloride in the surface water or the USCR watershed shall apply and supersede the existitHl regional water quality objectives .in._}'ab~_J-l 0 of the Basin }~an only when eh loride load FedttetioHs aHd/eF ehleriEie e~<f3ertf1ow-wei ghting proj ects are in operation bv SCVSD as described in the WLA section of this table and listed i11 ·:·able 7-6.2 . und reduce chloride loadiRg in aeeerdance '>vith the fellewirtg table: In addition. Qermit conditions will include ,12articiQation by SCVSD in the Salt and Nutrient Management Plan (SNMP) stakeholder-led group or other efforts to reduce the effects of the t'~Jt-~: ~SSOs and WLAs on the gualitv of the underlving groundwater basins. including the al luvial basins underlving Reaches 5 and 6 and the Saugus Formation.

n .1 . • C' .I, • £'1.,1 . . ,l, + f :ltleFiee l.ette Reduetiens~

4G mg/L < Q {i{i{i I I· ' ,I. ~ ~,

§G mg/L t:A fllili Jl. ,. ~

' C..{) . /1 7l ,GGG las , ). vv ' ' 6'~

'7li . / T '7'7 lili li IL month . ~.1:::

0{) • I Q'l_[l[)fl J ~ •• · ~ v. ' v •v · ~~ r~· .. •v . ...

9G mg/L Oli lilili II- 11-

'


I J()() . /I I ()£: (){){) I L .r. .. tlt I TVV UOf",l U . ·~ ... +Based on measured chloride ofthe State Water Project (SWP) water st:ored ifl Gastaic bal.:e. ~ GhloriEie load reductio A is eased Of! O:J3CrattOH of a R:G treati'Aent r laHt t:reatiAg 3 MG9 oft"ec,'clee '<'vater with chloride coHceAtra!ioA of §9 l'flg,q~ =F lNater Suj3ply GhloriEie. A:sSHffies O:f3CrHtiofiHI cat)acit:;' facter ef 99% and RG ffieffiarane chloriEie rejeetiol'l rate of 9§%. Deterffiination of chloriEie loaEI baseEI on the fo llmving:

ChlorideLotttl 90% )( Wuo )( c,VRP X 8.34)>< r]>< eoDayl~onth) 'NAcre F % chloriEie rejectioA (9§%) {'\ 3 ~·!GO of recycled water treated

with RG GwRP----- SWP Gl + 50 mg/6

Get1ditiB-Attl--Wb-A-s-~~1r-t.fle-..'JaugU:S-tlfid..-¥a.l-et1el-tl-WR:l2s-wfl+-he iffij31~ffiCHtCS throtlgh ef!'l UCHt ! i lflit~;, n~o11itori 11g l'~Ej!:!iFCIT!Cfi!S i I~ ~I~ f3Cf1Hit~; . GoAElitieAal l.VbAs ffir Reach 'I B wi II ae impleA~CflteEI as reeei'l'iAg wateF li!Tlits. GonditioAal V·/LAs for Reaches 5 and 6 v>ill be implementeEI as effluent limits.

'±'he it'Tl:flleffieAtatioH 13lafl :J3rOj3oses that duriAg the j3erioEI of +M9b ii'AJ3IeJ'ACAtatioH. Prior to the deadl ine for achieving the final conditional WLAs. compliance for the WRPs ' effluent limits will shall be evaluated relative to theiR uceordance with interim WLAs. below.

8augus WRP:

The interim WLA§ for chloride fcwthe_S.Q.!J.gus and Vnlenci_<L:YYR~2..tsare equal to the interim effluent limit~ for chloride specified in~

Resolution No. R4-2004-004. However. Qrior to the issuance/reissuance of the Saugus and Valencia NPDES Qermits. S_CVSD shall. t~w each_ WRP. submit recent QOtable water chloride concentration data. final effluent chloride data. and the change between the two. These data shall be used to recalculate the interim effluent limits during the NPDES Qermit renewallreissuance .Qrocess to reflect current water guality conditions. +he iAtel'ifH ~VbA fof +OS i5 I OQQ A'lg/L as an am~ual u•rerage. +Fie iHterii'A Wb~ fer s~::!!fate is 459 mg,ib as aH aAnual a•.-terage. 'fhese iAterim 1J/LAs shall Hf3f3ly as iAteriffi eH:d of :13if3e efAueAt limits, inteFim grouAd·~\>ater limits, aHEI iflterii'A liffiits in the NoR }JP9158 }}/9R: fer recycled •.vater uses from the SaugHs 'NRP iAstead of existing '<\'ater quality objectives.

ValeAcia WJ{:P:

Monitoring

Reso lution No. R4-20 14-0 I 0 Page 14

The interim \VL:\ for chloride i!, equul 1o tht' interim limit f<w ehltlride ~~e-ifiet+in·-tlf'€.1~r-J:>.ifl"-R-4-04-0{I-'h--+11e iA1:erim -W:bA fer +Q8 is 1 QQQ mg/6 as an annHal a•,•emge. 'fi:!e interim \\Lb6c, fer stt lfate is 4§Q mg/b as aA aAFHml a~·erage . +hese iA:t:erim },!/bAs shall at3J3Iy as iHterim eAEI ef t3if3e effiHeAt limits, interim greuAEiwat:er limits. aAEl interim litTi il:s iH t:i:!e f'!>len f'!>iPf)£8 1.¥9R fer reeyelea water Hses frem t:he ValeAeia WRP ffi.sread ef m<istiAg \Vater quality ebjeetives.

Other Major NPDES Permits (including Newhall Ranch WRP):

WLAs for other NPDES discharges will be implemented through effluent limits. monitorinll rcguirements. and other permit conditions in NPDES ~JJ11ith...+he R:egienal--Bean:J maJ' eettStder-a-ss-it~~"tmEJ.itie.nal WbA:; fm other n~ajflr NPJ.:)E£ f1ermits. ineh:tdiAg tile Ne'<'ifHtlll~anefi WRP, peAding implementation of a chloride I"TtaSJ removal quantity lhat i~1 tWe·pEH't:i-t.mal-te-r-nuss-based-t:-l'l:ft.~fne-v-a.J--r-ei.ittir-eEI-.fHF-Hte-¥a.J.etlelli ~

SupplemeA:tal Water relenseEI to Rencfi 6 of SantH Clara River:

.J:n erder to aeeemmodate tHe Eliseharge ef Sl::lf3f3lemeBtal 'Nater to Reaefl 6, iHterifTI l;VbAs are provieea for s~::~lfate of 4§Q B~glb aHEI T9S ef l QQQ mg,lb as amutal a•,•erages. +he fiAal WbAs are CEtHal te the e1~:istiAg water quality objectives fer sulfate and T9S in Table 3 8 of the Basin Plan. T11e Ree:ienal Beare ma'<' re'<•ise tf.le ~HallNbA baseEI eB re'<•iew e~treAEI

'-' -monitoring Elata as EletaileEI in the menitering sectiofl ef ti:!is BasiA Plan aJTiendn'l:enL

NPDES monitoring: NPDES Permittees will conduct chloride ehloride, TH8, aBEl su lfate effluent and receiving water monitoring to ensure that chloride \.~'U.er guality g_Q.i§S:.tiv~s and water Etl:lality ebjecti>o•eswaste load allocations are being met.

Trend monitorin g: The SCVSD will submit to the Regional Board and implement upon approval a monitoring plan to conduct chloride~ and s~::~ lfnt:e trend monitoring to ensure that the goal of chloride exf3of!:--i.n the wutershed is being achieves, water quality objectives and \vastc load al localion;i_are being met, i.lfl&.downstream groundwater ana surface water quality is not degraded. and groundwater underlving Reach 5 upstream of the Valencia WRP outfall 001 and Reach 6 is not degraded due to implementation of compliance measuresJ2.)::_S_C.VSJ2. __ +he 8C¥SQ f'I'WAitofiA g plaA shall iAe lttde f3laFts to ITIOAiter ehleriEle, +9S, anEI sulfate in f,'TBUASV<"ater aAEl identify representative wells to be appreved by tf.le Reeienal Beare B*ee~::~ti•{e Gffieer in the ·follewing locations: Ea~ 8hallew

Margin of Safety


alltl~' it:HH layer iA east PiFt:t BasiA, E87 SaA Pedro FermatieB iA east Piru BasiA. aHEI tCJ grotmd't'l•ater easiAS I:!Ader Reaches 3 aAd e, •n•hiel~ sl~all ae eE]I:!i¥aleAt er greater ti:laA e~~:istiAg grel:lAd•.vater meAiteriAg reE]tlired ey l'WDES permits fer Saugus aAEi Valencia WRPs. The monitoring plan shall a-1-s&-include a plan to collect water samples and analyze them for chloride, +DS, and stllfate tfeAEI meAiteriAg fer .in_surface water for Reaches 4B, 5~ and 67 The monitoring plun shall inc lude plaAs to moni~or chloride, TDS, and ~'ul fate at a minimum of once per quarter for gro~:~Advlulet'--!lnd at a min imum of once per month. and in groundwater in the alluvial basins underlying Reaches 5 and 6 and the Saue:us Aguifer at a minimum of twice 12er vear fer Stlrface •,r.;ater. At a minim um, the monitoring glan should include a network of three groundwater wells with multigle screens to evaluate imgacts to !.!Totmdwater. The plan should include pmpose a monitoring schedule that extends beyond the final imglementation dead line eemplel ieA Elate of this TMDL to suggort continual eval1:1ate evaluation of impacts of compliance measures to downstfeum gro1:1ndwater aAd surface water and groundwater qual ity. This TMDL shall be reconsidered if chloride~ TDS, and su lfate trend monitoring indicates degradation of groundwater or surface water due to implementation of compliance measures .

TrenEI menitoriAg: ·rhe Reael:! qA Permittee will s~:~l3 t~it a moAitering platt to eoAdl:!et chloride, TDS. aAd sttlfate treHd l~eAitoFiAg to ensttre ttl at ttle goal otel=!leriEie e~~:pot:t: iA the watersl=!eEI is aeiAg achie•.•eEI .• ,.,·ffier E]Uality o9jecti¥eS are aeiAg met, aAa aOWAStFeam grot:md•.;oater and Sl:ll"ffiee 'l't'ffier Ejttailt;• is A81 aegraeJed due te iiTiple!~eAI:atieH Of C8mf3JiaACe lfleGSHres. +i:le R:eaeh 4A 13eFmittee meAi~eriAg plaA si:lall iAeiHde plaAs te menitor chloride. :ros, a11d stt lfate iA greHAdwater aAd iEieAtif;· represeAtati•,•e '+''ells to ae appt·ovea a:r tAe R:egienal BoaFEI E}i:eCI:I~i~t•e Qffieer iA the fellowiHg loeatieAs ~a1 ~i l lmore BasiA, aAd E9) SaAta PaHia BasiA. +he meAi!:oriAg 13laA shall alse iAeiHde a plaA fer chloride, :ros, and s1:1lfate tFeAd HleAiteriHg fer stiFface water fer R:eaei:les;; aAEI 4A. +l:le ITIOAiteriAg plaA shoHIEI ii~CIHEie plaAs te meAiter ehleride. TDS, ana Sl:! lffite at fl miAiA'\I:!ITI of eAce 13er EJI:!aFter fur grottAEI:water aAd at a miA imum e~ eAce f'eF moAth fel' sudace •,rt~ater . +l~e pluA sl'ietti El prepese a meniterit'lg !3€1'\eEittle that s!:lall e~tteB:d eeyeRd tl1e 681'ApletieH Elate ef this Tl\H:)b to e.,·altta~e i1T113ae~s e~ cemf.ll iaAee !Tieasttres to dowAStFeam gFettAdwateF aAEI sHrfaee water EJttality. This :rM9b shall ae reeeAsidereel ifcl~loFiEie, +DS, aHEI s~:~ lffite tFeAd meniteFiAg iAaicates ElegradatioA efgFOt!Adw'ater er s~:~rfaee '•'rffief El1:1e te iA'lJ3Iel~eAtatioA ofco!TipliaAee !TieasttFes.

An imglicit margin of safety is incm:gorated through conservative model assumQtions and statistical analvsis. An i1'Aplieit margiH e~ safety is iACOfj98Fated t l~rough ceAservati.,•e moael assumptions and chloride mass aalaAee aAalysis. +he meael is an i11tegrateEI grotlfiElwateF s~:~rfaee wuter lfloael '•'<Aiel'\ shO'<'vS thut chloride

Seasonal Variations and Critical Conditions


Eiisel:!argee :ft:em tAe WR:Ps aeelimHiates iA tAe east PirH :BasiH. ~1:1rther

mass 8alaAee aAalysis sl~e'•'~'S tl:!at: tl:!e eh:!eriee n~ass reme'<•ee rretfl tl:!e Pir1:1 BasiA e~eeeEis tl'le ehleriee leased iAte tl:le Pir1:1 BasiA :ft:em imj9lemeAtatieA 8f ti:le eena itienal SSGs.

During dry weather conditions, less surface flow is available to dilute effluent discharge, groundwater pumping rates for agricultural purposes are higher, groundwater discharge is lower, poorer quality groundwater may be drawn into the aquifer, and evapotranspiration effects are greater than in wet weather conditions. During drought, reduced surface flow and increased groundwater extraction continues through several seasons with greater impacts on groundwater resources and discharges. -Dry and critically dry periods affecting the Sacramento and San Joaquin River Valleys reduce fresh-water flow into the Sacramento-San Joaquin Delta and result in higher than normal chloride concentrations in the State Water Project supply with in the California aqueduct system. -These increased chloride levels are transferred to the upper Santa Clara River. +l:!is eFitieal eet'lEii!ieH is ElefiAeEI as '•'<ReA \Vater SI:!J9J9I;r eeReeH~ratieRs meas11red in Castaie Lake are > 80 mg/L.

These critical conditions were included in the GSWI model to determine appropriate all ocations and implementation scenarios for the TMDL.


lementation Schcdul.5,

Im lementation Tasks 1. A lternate Water Supply

a) Should (1) the in-river concentratio n at Blue Cut, the Reach 4B boundary, exceed the water quality ob jective of 100 rng/Lconditional SSO of 117 mg/6, measured for the purposes of this TMDL as a rolling three-month rolling average, (2) each agricultural diverter provide records of the diversion dates and amounts to the Regional Board and Santa Clarita Valley County Sanitation Districts of Los Angeles County (SCVSD) for at least 2 years after the effective date of the TMDL and (3) each agricultural diverter provides photographic evidence that diverted water is applied to avocado, strawberry or other chloride sensitive crop and evidence of a water right to divert, then the SCVSD will be responsible for providing an alternative water supply, negotiating the delivery of alternative water by a third party, or providing fiscal remediation to be quantified in negotiations between the SCVSD and the agricu ltural dive1ter at the direction of the Regional Water Quality Control Board until such time as the in-river chloride concentrations do not exceed the e®naiti®nal SSO.

b) Should the instream concentration exceed 230 mg/L more than two times in the three year period, the di scharger identified by the Regional Board Executive Officer sha ll be required to submit, w ithin ninety days of a request by the Regional Board Executive Officer, a workplan for an accelerated schedule to reduce chloride discharges.

2. Progress reports will be submitted by the SCVSD to Regional Board staffeR a semiaA:Rual basis from the effective dute ofthe TMDL for tasks 4, 6, and 7, and on an annual basis for Tasks 5 and 11.

Progress reports will be submitted by the Reach 4/\ Permittee to Reaional Board staff on an annual basis for Task 12.

3. Chloride Source Identification/Reduction, Pollution PreventioR and Public Outreach P lan: Six months after the effective date of the TMDL the SCVSD wi ll submit a plan to the Regional Board that addresses measures taken and plaRned to be taken to quantify and control sources of chloride. iRcluding, but not limited to: execute coa1munity wide outreach programs, wh ich 't'iere developed based on the pilol outreach efforts conducted by the SCVSD, assess potential incentive/disincentive programs ror residential self regenerating

Completion Date

Effective Date of TMDb EOS/04/20057 (.! )~L11Q!JU2P.J.l upon completion of Task 4)

Semiannually and annually

6 moRths after Effective Date of TMDL (11 /04/2005)


1m lementation Tasks control ling chloride. The SCVSD shall develop and implement the source reduction/pollution prevention and public outreach program, and report results annually thereafter to the Regional Board. Chloride sources from imported w!lter supplies will be assessed. The assessment will include conditions of drought and low rainfalL and will analyze the alternatives for reduc iAg this source.

4. The SCVSD will coAvene a technical advisory committee or committees (TAC(s)) in cooperat ion 'Nith the Regional Board to re~· iew literature develop a methodology for assessment and provide recommendations \Vith detailed timelines and task descriptions to suppott any needed changes to the time schedule for evaluation of appropriate ch loride threshold for Task 6. The Regional Board, at a public hearing ·.vill re evaluate the schedule for Task 6 and subsequent linked tasks based on input from the TAC(s), along with Regional Board staff analysis and assessment consistent vtith state and federal law, as to the types of studies needed and the time needed to conduct the necessary scientific studies to determine the app!=ej:H:'iate chloride tl~H:J:ie-prffie€.oon of salt sensitive agricu ltural uses, aAd will take action to amend the schedule ifthere is sufficient technical justification.

5. Ground\vater/Surface Wuler Interaction Model: The SCVSD ·.viii solicit proposals. collect data, deYelop a n~odel in cooperation with the Regional Board, obtain peer review. and report results. The impact of source v,caters and reclaimed water plans on achievina the water qua lity objective and protecting beneficial uses. iacludin~ impacts on underlying groundwater quality. will also be assessed and specific reeommendatioAs for management de.,'eloped for Regional Board consideration. The purpose of the modeling and sampling effort is to determine the interaction between surface \Vater and groundvvnter as it may affect the loading of chloride from groundwater and its linkage to surfuee water quality.

6. evaluation of Appropriate Chloride Threshold for the Protection of Sensitive Agricultural Supply Use and Endangered Species Protection: The SCVSD will prepare and submit a repott on endangered species protection thresholds. The SCVSD 'Nill also prepare and submit a report presenting the results of the evaluation of chloride thresholds for salt seAsitive agricultural uses, which shall consider the impact of drought and IOV•' rainfall conditions and the associated increase in imp01ted water concentrations on dowAstream

CompJetion Date

12 months after Effective Date (05/04 /2006)

2.5 years after Effective Date of TMDL (11 /20/2007)

2.5 years after effective Date of TMDL ( I I /20/2007)


1m lementation Tasks

7. Develop SSO for Chloride for Sensitive Agriculture: The SCVSD \Nill solicit proposals and develop technicalnnalyses upon which the Regional Board may base n Basil'! Plan umendment.

8. Develop AAti Degra:dHtion Analysis for Revision of Chloride Objective by SSO: The SCVSD 'Ni l! sol icit proposals and deve lop draft anti degradation analysis for Regional Board consideration.

9. Develop a pre planning report on conceptual compliance measures to meet different hypothetical final conditioAal wasteload allocatioAs. The SCVSD shall solicit proposals and develop and submit a report to the Regional Board that identifies potential chloride control measures and costs based on different hypothetical scenarios for chloride SSOs and final conditional wasteload allocations.

10. a) Preparntion and Consideration of a Basin Plan .Amendment (BPA) to rev ise the chloride objecti'f·e by the Regional Board.

b) Evuluntion of Alternative Water Supplies for Agricultural Beneficial Uses: The SCVSD wtl-kjtHffitify water needs, identify alternative water supplies, evaluate necessary facilities, and report results. including the long term application of this remedy.

c) Analysis of Feasible Compliance Measures to Meet Final CoAditional Wasteload Allocations for Proposed Chloride Objective. The SCVSD '<Viii assess and report on feasible implementation actions to meet the chloride objective established pursuant to Task +Gat:

d) Reconsideration of and action taken on the Chloride TMDL and Final Conditional Wasteloud Allocotions for the Upper Santa Clara River by the Regional Bom·d.

2.-l-h-Trend monitoring: The SCVSD will submit to the Regional Board and upon approval implement a revised monitoring plan to conduct chloride, TDS, and sulfate trend monitoring to ensure that the goal of chloride e><porl in the watershed is being achieved, water quality objectives and waste oad allo~.,at1ons are being met, afltl. downstream ground'>vater and surface water quality is not degraded,_ and 2:roundwater underlving Reach 5 upstream of the Valencia WRP outfall 001 and Reach 6 is not deg:raded due to im lementation of

Completion Date

2.8 years after Effective Date of TMDL (02/20/2008)

3 .5 years after Effective Date of TMDL (12111/2008)

9/30/20154 years after Effective Date ofTMDL (05/0'1/2009)

Resolution No. R4-20 I 4-0 I 0 Page 19

Im lementation Tasks compliance measures by SCVSD. The monitoring plan shall include a plan to collect water 'jampl:.·s and analvze them for chloride in surface water for Reaches 48. 5. and 6 at a minimum of once per month. The monitoring plan shall also include a plan for chloride trend monitoring in the alluvial groundwater basins underlying Reaches 5 and 6 and in the Saugus Aquifer at a minimum oft\vice a year. At a minimum, the monitoring plan should include a network of three groundwater wells with multiple screens to evaluate impacts to groundwater. The SCVSD monitoring plan shall include plans to monitor chloride, TDS, and su lfate in ground'lvater and identify representative 'Neils to be approved by the Regional Board Executive Officer, in the fo llowing locations: (a) Shallow alluvium layer in east Piru Basin, (b) San Pedro Formation in enst Pin1 Basin, and (c) grouBd"Vvater basins under Reaches 5 nnd 6, which shall be equivalent or greater than existing groundwater monitoring required by NPDES ~rmits for Saugus and Valencia WRPs. The monitoring plan shall also include a plan for chloride, TDS, and sulfa!e trend monitoring for surface \Nater for Reaches 4B, 5 and 6. The monitoring plnn shall include plans to monitor ch loride, TD8, nnd sulfate at a minimum of once per quarter for groundvl"ater and at a minimum of once per month fer surface 'Nater. The plan should proposewi ll include a monitoring schedule that extends beyond the completion datefinal implementation deadline of this TMDL to suppot1 continual evaluate evaluation of impacts of com pi iance measures to downstream groundwater and surface water and groundwater quality. -This TMDL shall be reconsidered if ch loride, TDS, and sttlfate trend monitoring indicates degradation of groundwater or surface water due to implementation of compliance measures.

Completion Date

] 2. Trend monitoring: The Reach 4A Permittee will submit a monitoring Submitted ·.vith p-lan to conduct chloride, TDS, and sulfate trend monitoring to ensure permit applieatiott that the goal of chloride export in the watershed b being rtchieved, water qua+ity objectives are being met, and downstream groundwater-and surface \Vater quality is not degraded due to implementation of compliance measures. The Reach 4A pem1ittee monitoring plan shall include plans to monitor chloride, TDS, and sulfate in ground\vater and identify representative ·.veils to be approved by the Regional Board Executive Officer in the fello·Ning locations (a) Fillmore Basin, and (b) Santa Paula Basin. The monitoring plan shall also include a plan for chloride, TDS, and sui fate trend monitoring for ~hes 3 and 4A . The monitoring plan should ~le plans to monitor chloride, TDS, and sulfate at a minimum of

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Implementation Tasks tTI:oAtA fer sttrfaee 1-vater. :n'le fllaA shoula fJfOfJose a A~oAitoriRg sehee~ile tJuit shall e~<l:eAa eeyoAS the 60ffiJ3IetiOA date of this :.J=~ffib to C'f·alttute imj3aets of eemj3liaHee measHres to Elo"'•'AStFeatT! grett REl •Nater at'lEI sttrfuee :;vateF E}tHtl it:y. +!:lis JM9L sl~al lee

reeoA:sideree i:f ei:!lofiEie, +9g, ana sttlfate tFeAEi moAiteriAg iReieates eegmdutien of groundwater or surface ·.vuter dtte to imj31ementation of eotTI:fl liaAee measttres.

th 3. Begin monitoring per approved &V-{;&B=SCV.SD revised monitoring plan completed in Task ++~.

14. BegiH monitoring 13er approveEl Reach 4A Pern=tittee monitoring fJlaA:.

I§. aj ltTI !3leA~eRtation of Gom£3!ianee Measures, PlaABiAg: +lqe 8G¥St> shall s~:t~fHit a ret3eft ElffllttAHiAg aeti'l-• ities 'NAiek iAel ~:tde I:H:It are Hot: liFAitee to: E 11 ieeHtifyiAg lead state#eeeral ageBeies; (~j aE!miAisteriHg a 00ffij3etiti•,•e aiEl fli'OCCSS for the selection of e lR/ElS aAEl eHgiAeeriRg bORSHitaHts; (~j De\>'CIOf3FAeAt e:f ~aHa Feasil3ilitJ' ,<\Aai)'Ses; (4~ S~:tblflit:tal ef Prejeet f!.Jet:iee ef Pret'aHttioH.L~Jetiee of fflteHt:; (§1 PrefJaFatieB of Draft Wa~;tewater Faeili~ies PlaA aHa ProgratnFAatie BIR; (61 AEimiAistratieA of PLiblie R::e¥ie'l1< aHa Ge1'H:A-1ent Perioss; F1 9e¥elepmet~t of FiAal \Vast:ewater Facilities PlaA aAEl PregraFAFAatie 5IR:: aRe iHeerporatien aRe rest3eBse te eoFAFAeRts; (81 Ae1niHist:ratieH ef HAal pttl:llie re'~>' i e•N ~:mEl eertifieatio1:1 precess; aAd (9j Filing a Notiee e:fDetermination ana Record of DeeisieA.

13) IFAfl lemeAtatioA of Gemplianee Meast1res, Pla11 1~ iAg: +11e S{;\L£D shall pro¥iee a seJqeettle of related tasl~s ana s~:tbtasl.:s related te :J:'ask 15a), and t3rovide semi aRnual t3regress reports en progress of 17~aA:Ring aeti'l-•ities, thereafter, Hflttl-eeH-lfrletien of Final 'N ustev.,·ater Facilities PitH~ and Programmatic EUt

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Reso lution No. R4-201 4-0l 0 Page 19

Completion Date

Six monthsGne ~·ear after Executive Officer approval of Task ++-2 revised monitoring plan for SCVSD

GAe year after b}i:ectttive GFficer appFe¥al Of +as I<: l ~ ITI:oAiteriAg J3ltm fur Reael1 4 A Permittee

§ years aft:et= Effeet:i¥e Dnte of +M9b (0904/20 I 01

§ years af::er EffectiYe Date of JM&b (0§/04/~0 I 01

c. rs after


Im lemeotation Tasks iffij91Cffient control measures needed to meet final condi tional WLAs adopted pursuant to Task 10 d) and the schedule for Task 17. The Regional Board, at a public meeting will consider e~ctending the completio11 date of Tusk 17 and reconsider the schedule to implement control measures to meet final conditional WLAs adopted pursuant to Task I 0 d). The SCVSD will provide the justification fer the need for an e)ctens ion to the Regional Board EKecutive Officer at least 6 months in advance of the deadline fer this task.

17.a) Implementation of Compliance Measures, Complete Enviro11mental Impact Report: The SCVSD shall complete a Wastewater Facilities Plan and Programmatic Environffiental Impact Report fer facilities to comply with final effluent permit limits for chloride.

b)lmplementation of Compliance Measures, Engi11eering Design: The SCVSD \Yill begin the engineering design of the recommended project 'tVastev.-ater facilities.

e) lmplementntion of Compliunce Measures, Engineering Design: The SCVSD will provide a design schedule of related tasks and sub tasks. and provide semi annual progress reports on progress of design activities, thereafter, until completion affinal Design. In addition the SCVSD will provide a construction schedule of related tusks and sub tasks, and provide semi a11nual progress repetts on progress of construction activities, thereafter, until completio11 of recommerided project ·.vastewater facilities.

d)lmplementation ofCompliance Measures. Construction: The SCVSD shall have applied and received all appropriate permits and have completed construction ofthe recommended project wastewater facilities.

e)lmplementation of Compliance Measures, Start Up: The SCVSD shall have completed stal'H:tj:>, testing and certification of the recommended project vrustewater facil ities.

4. Implementation of Compliance Measures bv SCYSD

a) Deep Well Injection Test Well

i.Complete design for deep well test well

Completion Date

Effective Date of TMDL (05/04/20 ll)

6 years af1er Effective Date of TMDL (05/04/20 I I)

6 years after Effective Date of TMDL (05/04/2011)

7 years ttfter Etiective Date of TMDL (05/04/2012)

9.5 years after Effect ive Date of TMDL ( 11/04/20 14)

1 0 years after Effective Date of TMDL (05/04 /2015

09/30115

Im lementation Tasks i i .A ward contract for deep well injection test well

iii.Construction and testing of test well

b) UV Disinfection Facil ities at Valencia and Sawws WRPs

i.Complete design of UV disinfection facilities

ii.Award contract for UV disinfection faci lit ies

iii.Start onsite construction of UV disinfection facilities

iv.Start-up ofUV disinfection facilities

c) Microfiltration/Reverse Osmosis (MF/RO) and Brine Minimization Facil ities


Completion Date

01 /20/ 16

II /08/ 16

4/12/2017

7/ 10/2017

3/ 10/2018

7/ 112019

i.Complete design of MF/RO and brine minimization faci lities 4/12/2017

ii.Award contract for MF/RO and brine mini mization facilities 7/ 10/2017

iii .Start onsite construction of MF/RO and brine minimization 3/ l 0/2018 fac ilities

iv.Start-up ofMF/RO and brine minimization facilities 7/ 1/2019

d) Final Deep Well Injection Production Wells

i.Complete design for the final deep well injection production wells

ii .Start onsite construction

iii.Start-up of the deep well injection production wells

e) Brine Force Main and Pump Station

i.Complete 50% design of brine force main and pump station

ii.Complete design of brine force main and pump station

iii.Start-up of the brine force main and pump station

The Reaional Board mav consider extend in(' some of the com let ion

6/6/20 17

12/29/'10 18

7/ 1/2019

11 /6/2017

5/6/2018

711 /2019

tH - .fi."'l .J.. ~,

' . .... ~ .... -CI-tlflt R .r 1-..funJt: l ~,.;Db

Implementation Tasks


Completion Date

dates of this task as necessary to account for events beyond the control of the SCVSD. 5. Progress reQorts will be submitted by the SCVSD to the Regional Semiannually fo r

Board on a semiannual basis for Task 4 and an annual basis for Task Task 4 (1 0/3 1/15. 3. ProJJ.ress reQorts shall include supJ2orting documentation that tasks 4/30/ 16. I 0/3 1116. were comQieted bv the deadline. 4/30/ 17.10/3 1/17,

4/30/18, 10/31/ 18. 4/30/19, 1 0/31/ 19}; Annually for Task 3 (Eighteen months after Executive Offlcer aQQI'OYal of Task 2 monitoring Qlan for SCVSD. and annually thereafter)

-18.The Regional Board Ea<ecutive Officer may consider 7 years after €Effiattte-fH:tl--8-SGs-fut:...i=±-)S..a.f~ulfate fe r Reaches 4B, §, ana 6 Effective Dute of ear.;ed Ofl restllts 0~ gt·etmdwateF Stlrfaee '<'l"ater iHteraetien studies TM9b e-A aeCliiTH:Ilation o:j:+Q£ and Sl:l lfute in grollnEl¥iater, J38tential (05/04/20 12) ii'RJ3UCtS tO eenefieiaJ liSeS, !:lHd aH anti degt=adation UAUJj•sis.

19.+1:le Regional Boars staffwill re e'!'aluate tl:le sel:leel ~tle to 9.5 j'ears after im13 lement contro l measm·es needed ~e meet final eoHditieAal Effective Date of WbAs adopted f'I:IFSI:laAI: to +asiE: 1 Q el) anel tl:le sel:lesule fer +asl~ +MQb l+. +l:le Regional Beare. at a J3tt91 ie ffieetiRg will eoRsider (1 1/04 /2Q14) e~Hend iflg the eomJ3Ietion of:+asl.: I 7 aBEl reeoAsiEier the selledule te it'RJ3IetHen l: eofltrol meas~:~res l:e tflee~ HAul eenditieAal \¥LA:s aso13tes for ehloFiEie f31:11'Sllal~t l:e +as!< I 0 d) . +l:le SG.V8Q wil l f31'0¥iele the justifieation fuF the need ~ran C1<tensieA te the R:egioRal Board e1teet~ti .. •e O#ieer at least 6 moHtAS iR aEI't•anee ef the deodline for this tuslc. +he R:egional Board will ulso eonsieleF COAsitienal 88Gs aRe fiAal consitienal WbAs fer +08 aRe stt lfate bases en reslllts of+asl~ 18.

Q_,__~ The interim WLAs for chloride sha ll remain in effect fuF....RB 1 0 :;•ears after mere than until the deadline for comQietion of the SCYSD flO\\ Effective Date of weighting Qroject facilities identified in Task 410 years after tl:le +MQb effective Elate of the TMDb. ' --- 'I:! ~JI. ~CYSD shall achieve (05/04/20 15) compliance with the Gt:mditienal SSGaQplicable ,~·ater guality 07/0 I /2019 objectives and WLAs for chloride in the USCR ~ilHtll bt· ael:lic...-ed . Final condition ·1 1111 A

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' '

Im lementation Tasks by May 5, 20 L5. The Regional Board mny consider extendiHg the completion date of this task as nece~;sary to account for events heyond the control ofthe SCVSD.

2l .The interim Wbi\s for TDS and su! fate contained in this BPA (Resolution }~o , R4 2008 0 L2) shall be implemented no sooner than the effective date ofthis BPA, and shall remain in effect until May 4. 2015. Final WLAs shall apply by May 5, 2015 unless conditional SSOs and final conditional WLAs for TDS and sulfate are adopted as described in Task 19.


Completion Date

I 0 years after Effective Dnte of TMDL (05/04/20 15)

apr 2015 samuel unger - california state water resources control board · santa clara ri"

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