The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE

OMB APPROVAL
OMB Number: 3235-0006
Estimated average burden
hours per response: 23.8

COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
3M Co Common 88579Y101 31,769 161,491 SH   SOLE 0 129,248 0 32,243
Acuity Brands Inc Common 00508Y102 60,531 522,403 SH   SOLE 0 319,425 0 202,978
Advanced Drainage Systems Inc Common 00790R104 110,739 3,878,781 SH   SOLE 0 3,024,270 0 854,511
AGCO Corp Common 001084102 14,573 240,000 SH   SOLE 0 240,000 0 0
Agilent Technologies Inc Common 00846U101 167,564 2,709,632 SH   SOLE 0 2,514,235 0 195,397
American Water Works Co Inc Common 030420103 198,268 2,322,179 SH   SOLE 0 2,000,501 0 321,678
AO Smith Corp Common 831865209 134,571 2,275,087 SH   SOLE 0 1,697,790 0 577,297
Aqua America Inc Common 03836W103 74,550 2,119,113 SH   SOLE 0 2,094,858 0 24,255
Autodesk Inc Common 052769106 50,447 384,826 SH   SOLE 0 209,718 0 175,108
Badger Meter Inc Common 056525108 62,340 1,394,629 SH   SOLE 0 1,219,767 0 174,862
Becton Dickinson and Co Common 075887109 909 3,793 SH   SOLE 0 3,793 0 0
Bemis Co Inc Common 081437105 16,124 382,000 SH   SOLE 0 382,000 0 0
BorgWarner Inc Common 099724106 18,227 422,316 SH   SOLE 0 327,455 0 94,861
Cadence Design Systems Inc Common 127387108 670 15,475 SH   SOLE 0 15,475 0 0
Campbell Soup Co Common 134429109 17,955 442,900 SH   SOLE 0 442,900 0 0
Cia de Saneamento Basico do Es ADR 20441A102 85,382 14,206,602 SH   SOLE 0 12,898,966 0 1,307,636
Clean Harbors Inc Common 184496107 20,222 364,035 SH   SOLE 0 174,164 0 189,871
Cognizant Technology Solutions Common 192446102 604 7,644 SH   SOLE 0 7,644 0 0
Danaher Corp Common 235851102 206,150 2,089,080 SH   SOLE 0 1,925,147 0 163,933
Darling Ingredients Inc Common 237266101 42,312 2,128,385 SH   SOLE 0 2,128,385 0 0
Donaldson Co Inc Common 257651109 14,820 328,462 SH   SOLE 0 160,877 0 167,585
Ecolab Inc Common 278865100 200,004 1,425,240 SH   SOLE 0 1,310,950 0 114,290
Flowserve Corp Common 34354P105 34,508 854,147 SH   SOLE 0 843,719 0 10,428
Fortive Corp Common 34959J108 24,501 317,740 SH   SOLE 0 227,094 0 90,646
Franklin Electric Co Inc Common 353514102 104,570 2,318,626 SH   SOLE 0 2,019,043 0 299,583
Generac Holdings Inc Common 368736104 48,574 938,982 SH   SOLE 0 668,208 0 270,774
HDFC Bank Ltd ADR 40415F101 1,110 10,574 SH   SOLE 0 10,574 0 0
Hubbell Inc Common 443510607 53,305 504,118 SH   SOLE 0 434,593 0 69,525
Ichor Holdings Ltd Common G4740B105 7,721 363,864 SH   SOLE 0 187,193 0 176,671
IDEX Corp Common 45167R104 145,276 1,064,447 SH   SOLE 0 975,346 0 89,101
Ingersoll-Rand PLC Common G47791101 65,721 732,432 SH   SOLE 0 583,846 0 148,586
Itron Inc Common 465741106 114,823 1,912,115 SH   SOLE 0 1,406,661 0 505,454
Johnson Controls International Common G51502105 17,163 513,096 SH   SOLE 0 30,043 0 483,053
Lennox International Inc Common 526107107 34,995 174,842 SH   SOLE 0 125,919 0 48,923
Lindsay Corp Common 535555106 71,131 733,387 SH   SOLE 0 510,149 0 223,238
Middlesex Water Co Common 596680108 10,944 259,513 SH   SOLE 0 0 0 259,513
Mueller Water Products Inc Common 624758108 84,835 7,238,486 SH   SOLE 0 7,149,394 0 89,092
Oracle Corp Common 68389X105 593 13,469 SH   SOLE 0 13,469 0 0
Ormat Technologies Inc Common 686688102 46,936 882,419 SH   SOLE 0 615,025 0 267,394
PerkinElmer Inc Common 714046109 70,999 969,533 SH   SOLE 0 957,473 0 12,060
Pool Corp Common 73278L105 59,491 392,682 SH   SOLE 0 387,862 0 4,820
Power Integrations Inc Common 739276103 66,123 905,176 SH   SOLE 0 421,093 0 484,083
Praxair Inc Common 74005P104 70,548 446,081 SH   SOLE 0 359,213 0 86,868
PTC Inc Common 69370C100 98,015 1,044,823 SH   SOLE 0 778,313 0 266,510
Rayonier Inc Common 754907103 40,269 1,040,819 SH   SOLE 0 730,759 0 310,060
Rexnord Corp Common 76169B102 91,333 3,142,926 SH   SOLE 0 3,104,675 0 38,251
Sealed Air Corp Common 81211K100 113,204 2,666,755 SH   SOLE 0 2,253,116 0 413,639
Sensata Technologies Holding P Common G8060N102 36,179 760,393 SH   SOLE 0 499,659 0 260,734
Sonoco Products Co Common 835495102 25,710 489,710 SH   SOLE 0 489,710 0 0
Sprouts Farmers Market Inc Common 85208M102 23,504 1,064,959 SH   SOLE 0 1,064,959 0 0
SPX FLOW Inc Common 78469X107 36,276 828,797 SH   SOLE 0 818,610 0 10,187
Starbucks Corp Common 855244109 16,907 346,104 SH   SOLE 0 346,104 0 0
SunPower Corp Common 867652406 22,761 2,967,499 SH   SOLE 0 1,448,777 0 1,518,722
Thermo Fisher Scientific Inc Common 883556102 1,054 5,088 SH   SOLE 0 5,088 0 0
Toro Co/The Common 891092108 55,348 918,641 SH   SOLE 0 907,345 0 11,296
Trimble Inc Common 896239100 152,015 4,628,971 SH   SOLE 0 3,992,123 0 636,848
United Natural Foods Inc Common 911163103 32,645 765,242 SH   SOLE 0 523,117 0 242,125
Valmont Industries Inc Common 920253101 90,562 600,745 SH   SOLE 0 441,291 0 159,454
Visa Inc Common 92826C839 1,505 11,362 SH   SOLE 0 11,362 0 0
Waste Management Inc Common 94106L109 57,653 708,788 SH   SOLE 0 566,379 0 142,409
Waters Corp Common 941848103 51,663 266,868 SH   SOLE 0 214,688 0 52,180
Watts Water Technologies Inc Common 942749102 166,774 2,127,222 SH   SOLE 0 1,573,822 0 553,400
Welbilt Inc Common 949090104 64,763 2,902,886 SH   SOLE 0 2,238,127 0 664,759
WestRock Co Common 96145D105 80,986 1,420,306 SH   SOLE 0 1,220,150 0 200,156
Xylem Inc/NY Common 98419M100 195,590 2,902,789 SH   SOLE 0 2,524,872 0 377,917