{"transactions":[{"id":4166603,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"exercise","acquired":false,"shares":20875,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The option was fully exercisable on November 16, 2016."}],"balance_after":0,"derivative":{"exercise_price":24.26,"exercise_date":"2016-11-16","expiration_date":"2020-11-16","underlying":"COMMON STOCK","underlying_shares":20875},"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4166602,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"exercise","acquired":false,"shares":21520,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The option was fully exercisable on November 11, 2015."}],"balance_after":0,"derivative":{"exercise_price":22.53,"exercise_date":"2015-11-11","expiration_date":"2019-11-11","underlying":"COMMON STOCK","underlying_shares":21520},"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4166601,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"sale","acquired":false,"shares":20875,"price":50,"value":1043750.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"All shares sold at an exact price, pursuant to an automatic 10b5-1 trading plan."}],"balance_after":37104,"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4166600,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"sale","acquired":false,"shares":21520,"price":50,"value":1076000.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"All shares sold at an exact price, pursuant to an automatic 10b5-1 trading plan."}],"balance_after":57979,"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4166599,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"exercise","acquired":true,"shares":20875,"price":24.26,"value":506427.5,"ownership":{"direct":true},"balance_after":79499,"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4166598,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-11-14T00:11:12.000Z","date":"2017-11-09","kind":"exercise","acquired":true,"shares":21520,"price":22.53,"value":484845.6,"ownership":{"direct":true},"balance_after":58624,"source":{"system":"sec-edgar","filing":"0000831641-17-000008","document":"wf-form4_151061825816274.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000008/wf-form4_151061825816274.xml","form_type":"4"}},{"id":4177885,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2017-10-31T22:35:38.000Z","date":"2017-10-27","kind":"exercise","acquired":false,"shares":696,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The option was fully exercisable on November 11, 2015."}],"balance_after":21520,"derivative":{"exercise_price":22.53,"exercise_date":"2015-11-11","expiration_date":"2019-11-11","underlying":"COMMON STOCK","underlying_shares":696},"source":{"system":"sec-edgar","filing":"0000831641-17-000003","document":"wf-form4_150948932379893.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000003/wf-form4_150948932379893.xml","form_type":"4"}},{"id":4177884,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-10-31T22:35:38.000Z","date":"2017-10-27","kind":"sale","acquired":false,"shares":696,"price":50,"value":34800.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"All shares sold at an exact price, pursuant to an automatic 10b5-1 trading plan."}],"balance_after":37104,"source":{"system":"sec-edgar","filing":"0000831641-17-000003","document":"wf-form4_150948932379893.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000003/wf-form4_150948932379893.xml","form_type":"4"}},{"id":4177883,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-10-31T22:35:38.000Z","date":"2017-10-27","kind":"exercise","acquired":true,"shares":696,"price":22.53,"value":15680.88,"ownership":{"direct":true},"balance_after":37800,"source":{"system":"sec-edgar","filing":"0000831641-17-000003","document":"wf-form4_150948932379893.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000083164117000003/wf-form4_150948932379893.xml","form_type":"4"}},{"id":4180329,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2017-10-26T20:33:03.000Z","date":"2017-10-24","kind":"exercise","acquired":false,"shares":14112,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option was fully exercisable on November 11, 2015."}],"balance_after":22216,"derivative":{"exercise_price":22.53,"exercise_date":"2015-11-11","expiration_date":"2019-11-11","underlying":"COMMON STOCK","underlying_shares":14112},"source":{"system":"sec-edgar","filing":"0001450055-17-000003","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000003/edgar.xml","form_type":"4"}},{"id":4180328,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-10-26T20:33:03.000Z","date":"2017-10-24","kind":"sale","acquired":false,"shares":14112,"price":50,"value":705600.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"All shares were sold at an exact price pursuant to a 10b5-1 automatic trading plan."}],"balance_after":37104,"source":{"system":"sec-edgar","filing":"0001450055-17-000003","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000003/edgar.xml","form_type":"4"}},{"id":4180327,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-10-26T20:33:03.000Z","date":"2017-10-24","kind":"exercise","acquired":true,"shares":14112,"price":22.53,"value":317943.36,"ownership":{"direct":true},"balance_after":51216,"source":{"system":"sec-edgar","filing":"0001450055-17-000003","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000003/edgar.xml","form_type":"4"}},{"id":4332502,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2017-05-05T22:26:41.000Z","date":"2017-05-04","kind":"exercise","acquired":false,"shares":32951,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option was fully exercisable on November 12, 2014."}],"balance_after":0,"derivative":{"exercise_price":23.48,"exercise_date":"2014-11-12","expiration_date":"2018-11-12","underlying":"COMMON STOCK","underlying_shares":32951},"source":{"system":"sec-edgar","filing":"0001450055-17-000002","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000002/edgar.xml","form_type":"4"}},{"id":4332501,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-05-05T22:26:41.000Z","date":"2017-05-04","kind":"sale","acquired":false,"shares":32951,"price":46.0035,"value":1515861.3285,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"$46.0035 is a weighted average price.  These shares were sold in multiple transactions at prices ranging from $46.00 to $46.005 pursuant to a 10b5-1 automatic trading plan."}],"balance_after":37104,"source":{"system":"sec-edgar","filing":"0001450055-17-000002","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000002/edgar.xml","form_type":"4"}},{"id":4332500,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2017-05-05T22:26:41.000Z","date":"2017-05-04","kind":"exercise","acquired":false,"shares":32951,"price":23.48,"value":773689.48,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"In addition to the 32,951shares acquired in the option exercise, the reporting person acquired 192 shares of common stock pursuant to the company's Employee Stock Purchase Plan (ESPP) on December 15, 2016."}],"balance_after":70055,"source":{"system":"sec-edgar","filing":"0001450055-17-000002","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005517000002/edgar.xml","form_type":"4"}},{"id":4543953,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-23T21:37:02.000Z","date":"2016-11-22","kind":"tax_withholding","acquired":false,"shares":309,"price":42.8,"value":13225.2,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F4","text":"309 of the shares underlying RSUs which vested on 11/22/2016 were withheld to pay the related tax liability."}],"balance_after":36912,"source":{"system":"sec-edgar","filing":"0001450055-16-000012","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000012/edgar.xml","form_type":"4"}},{"id":4543952,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-23T21:37:02.000Z","date":"2016-11-22","kind":"tax_withholding","acquired":false,"shares":1154,"price":42.8,"value":49391.2,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"1,154 of the shares underlying restricted stock which vested on 11/22/2016 were withheld to pay the related tax liability."}],"balance_after":37221,"source":{"system":"sec-edgar","filing":"0001450055-16-000012","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000012/edgar.xml","form_type":"4"}},{"id":4543951,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-23T21:37:02.000Z","date":"2016-11-22","kind":"grant","acquired":true,"shares":1013,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"In accordance with the Executive Compensation Policy, 140% of one restricted stock installment granted on 11/22/2013 became vested on 11/22/2016, and 1,013 addtional shares were issued to the reporting person."}],"balance_after":38375,"source":{"system":"sec-edgar","filing":"0001450055-16-000012","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000012/edgar.xml","form_type":"4"}},{"id":4543950,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-23T21:37:02.000Z","date":"2016-11-21","kind":"tax_withholding","acquired":false,"shares":400,"price":41.25,"value":16500.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"400 of the shares underlying RSUs which vested on 11/21/2016 were withheld to pay the related tax liability."}],"balance_after":37362,"source":{"system":"sec-edgar","filing":"0001450055-16-000012","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000012/edgar.xml","form_type":"4"}},{"id":4546020,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"STOCK OPTION (RIGHT TO BUY)","published_at":"2016-11-22T23:52:33.000Z","date":"2016-11-18","kind":"grant","acquired":true,"shares":11427,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The option becomes exercisable as to 25% of the shares on each anniversary of the grant date."}],"balance_after":11427,"derivative":{"exercise_price":40.8,"exercise_date":"2017-11-18","expiration_date":"2026-11-18","underlying":"COMMON STOCK","underlying_shares":11427},"source":{"system":"sec-edgar","filing":"0001450055-16-000011","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000011/edgar.xml","form_type":"4"}},{"id":4546019,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-22T23:52:33.000Z","date":"2016-11-20","kind":"tax_withholding","acquired":false,"shares":434,"price":40.8,"value":17707.2,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"434 of the shares underlying RSUs which vested on 11/20/2016 were withheld to pay the related tax liability."}],"balance_after":37762,"source":{"system":"sec-edgar","filing":"0001450055-16-000011","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000011/edgar.xml","form_type":"4"}},{"id":4546018,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-22T23:52:33.000Z","date":"2016-11-18","kind":"grant","acquired":true,"shares":3451,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"3,451 restricted stock units (RSUs) were awarded to the reporting person on November 18, 2016.  The RSUs become vested as to 25% of the shares on each anniversary of the grant date."}],"balance_after":38196,"source":{"system":"sec-edgar","filing":"0001450055-16-000011","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000011/edgar.xml","form_type":"4"}},{"id":4551445,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"RESTRICTED STOCK UNITS","published_at":"2016-11-18T02:57:07.000Z","date":"2016-11-16","kind":"exercise","acquired":false,"shares":1043,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"On November 16, 2016, 1,043 restricted stock units (RSUs) awarded in November 2012 vested.  The shares of common stock into which such vested RSUs converted are reported in Table I of this Form 4."}],"balance_after":0,"derivative":{"exercise_price":0,"exercise_date":"2016-11-16","expiration_date":"2016-11-16","underlying":"COMMON STOCK","underlying_shares":1043},"source":{"system":"sec-edgar","filing":"0001450055-16-000010","document":"edgar.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000010/edgar.xml","form_type":"4"}},{"id":4551444,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-18T02:57:07.000Z","date":"2016-11-16","kind":"tax_withholding","acquired":false,"shares":339,"price":41.65,"value":14119.35,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F3","text":"On November 16, 2016, 1,043 restricted stock units (RSUs) awarded in November 2012 vested.  Of the vested RSUs, 339 underlying shares were withheld to pay the related tax liability."}],"balance_after":34745,"source":{"system":"sec-edgar","filing":"0001450055-16-000010","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000010/edgar.xml","form_type":"4"}},{"id":4551443,"issuer":{"id":3570,"kind":"organization","name":"TETRA TECH INC"},"owners":[{"id":171968,"kind":"person","name":"CHU RONALD J","position":1,"cik":"0001450055","reported_name":"CHU RONALD J","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EXECUTIVE VICE PRESIDENT"}}],"security":"COMMON STOCK","published_at":"2016-11-18T02:57:07.000Z","date":"2016-11-16","kind":"exercise","acquired":true,"shares":1043,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F2","text":"Represents the conversion upon vesting of restricted stock units into common stock."}],"balance_after":35084,"source":{"system":"sec-edgar","filing":"0001450055-16-000010","document":"edgar.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/831641/000145005516000010/edgar.xml","form_type":"4"}}]}