LIHI Certificate #92 - Pierce Mills Project, Vermont

Pierce Mills Project - LIHI Certificate #92
Nom du projet Pierce Mills
Numéro de certificat LIHI 92
Durée du certificat LIHI February 6, 2017 – February 5, 2030
Propriétaire Société d'énergie de Green Mountain
État Vermont
Emplacement Located at river mile 15.2 on the Passumpsic River, a tributary of the Connecticut River; the most upstream of the Passumpsic River Projects.
Capacité installée 250 kW
Génération annuelle moyenne 1 133 MWh
Type d'établissement Au fil de l'eau
Fédération internationale de radio-télévision (FERC) Non. P-2396 issued in 1994, expires 11/30/2034

The Pierce Mills Project is located in northeastern Vermont near St. Johnsbury, in Caledonia County, on the Passumpsic River. It was built in 1917-1919 by the Twin State Gas & Electric Company. The centrale was completely destroyed in the flood of 1927, although the concrete barrage was largely undamaged. The plant was rebuilt in 1928 utilizing portions of the earlier substructure.

The Passumpsic River is host to several dams of which the project is the fifth on the river.  Downstream are Arnold Falls (LIHI #93), Jauge (LIHI #94), Projet Passumpsic (LIHI #95) et East Barnet (FERC n° 3051), le premier barrage sur la rivière. La rivière mesure 36,5 km de long et est un affluent de la rivière Connecticut, entrant juste en aval de Comerford Barrage (une partie de la Projet des chutes de Fifteen Mile, LIHI #39). Le projet appartient à Green Mountain Power (GMP), le premier service public d'énergie certifié Société B.

The project includes: a dam, tableaux d'affichage, intake structure, powerhouse, one vertical turbine, sous-station, déversoir, and bypassed reach.

Le béton barrage-poids is 93-feet-long by18-feet-high, topped with 18-inch flashboards. A 37-foot-long intake structure forms the left pilier, with a manually operated bulkhead gate and trashrack. A 6-foot diameter, 246-foot-long wood stave conduite forcée conveys flows from the dam to the powerhouse. The powerhouse contains one vertical shaft turbine and generator with an installed capacity of 0.25 MW, along with appurtenant equipment.

Le projet opère dans un au fil de l'eau mode and impounds a 24.7-acre reservoir. The project provides a minimum flow of 20 cfs from April 1 through June 15 and from September 15 through November 15. Additionally, downstream passage des poissons is facilitated by an 88 cfs or inflow, whichever is less, passage flow. An aesthetic flow of 7 cfs is spilled over the flashboards from June 1 through October 31. These flow prescriptions were developed in consultation with the Vermont Agency of Natural Resources (VANR) and United States Fish and Wildlife Service.

Les eaux situées dans le périmètre du projet sont classées de classe B et contaminées par E. coli en raison du déversement des eaux usées de la station d'épuration de St. Johnsbury. VANR a confirmé que le projet n'a pas d'impact négatif sur la qualité de l'eau et n'est pas à l'origine de dégradations des cours d'eau. Les eaux de classe B sont gérées de manière à soutenir le biote aquatique, la faune et l'habitat aquatique, l'approvisionnement public en eau, l'irrigation, les loisirs de contact primaire et l'esthétique.

Alors que le Connecticut Bassin fluvial historiquement hébergées naturellement par des saumons de l'Atlantique, l'espèce était extirpé from the river system due to the construction of dams. These downstream dams create a barrier to upstream passage at the project. Downstream passage is facilitated year-round via a transition box located in the spillway with an 88 cfs passage flow which leads to a piscine de plongée. Trashracks with 1-inch spacing mitigate the potential for entraînement.

The project lands consist of 2.8 acres. The lands surrounding the project are primarily mixed industrial and commercial buildings, rural residential housing, and farmland, with no lands of significant ecological value in the project area.

Threatened or endangered species potentially present in the project vicinity include the Northern Long-eared Bat, Spikemoss, and Shining Lady’s Tresses. Significant habitat does exist in the project vicinity but consultation with VANR determined that these habitats would not be adversely impacted by project operations.

Les ressources culturelles dans la zone du projet comprennent l'infrastructure du projet qui est éligible à l'inscription sur la liste Registre national des lieux historiques. The project owner submits annual reports to the Vermont Division for Historic Preservation and conducts shoreline monitoring every three years to ensure that no known or potential archaeological sites are threatened by erosion events.

Recreational resources at the project include a canoe portage, fishing access, a camping area which is restricted to canoe/kayak through boaters for one night maximum, and a picnic area. Public access is provided free of charge.

PLUS-Standard: Criterion for LIHI certification include a PLUS standard for facilities that demonstrate substantial extra efforts in environmental and social mitigation, enhancement, or restoration. This project has achieved a PLUS standard by voluntarily making significant revisions to the Guide de canoë et de loisirs sur la rivière Passumpsic which provides the public with enhanced knowledge of recreation opportunities both on and off project lands and waters. The collaborative effort of the multi-party interest groups established that the public needed better information to enhance their recreational experiences.

État de conformité

Il n’y a pas de conditions spécifiques à l’établissement dans le certificat actuel.

2025: No material changes or compliance issues were identified. The project remains in compliance based on the annual review. The project reported that the plant was damaged during the July 2024 500-year flood event, and remains out of service.  Recreation areas were temporarily closed in 2024 for public safety reasons resulting from the flooding and were re-opened in the Fall of 2024.

2024: Aucun changement important ni problème de conformité n'ont été identifiés. Le projet reste conforme sur la base de l'examen annuel.

2023: Aucun changement important ni problème de conformité n'ont été identifiés. Le projet reste conforme sur la base de l'examen annuel.

2022: No material chances or compliance issues were identified. The project remains in compliance based on the annual review. Of note, the next upstream hydro project (Great Falls, P-2839) received a new FERC license in 2020 that increased its minimum bypass flow from 10 to 62 cfs.

2021: There were no report changes or compliance issues. The project remains in compliance based on the annual review.

2020: There were no report changes or compliance issues. The project remains in compliance based on the annual review.

2019: There were no report changes or compliance issues. The project remains in compliance based on the annual review.

2018: The project reported relocation of public parking, pedestrian access, and signage from the powerhouse area to 1/4 mile north at Highway 15 due to vandalism at the original site. A revised recreation plan was approved by FERC in 2017. The project remains in compliance based on the annual review.

2017: Le rapport annuel pour le certificat actuel n’est pas encore entré en vigueur.

Historique des certifications

1er janvier 2022 : La durée du certificat LIHI a été prolongée conformément à la révision 2.05 du manuel de certification LIHI 2e édition publié le 1er janvier 2022. Reportez-vous au tableau des établissements ci-dessus pour connaître la nouvelle durée.

15 août 2018 : The decision to recertify the Pierce Mills Hydroelectric Project is final. No appeals were received during the appeal period which closed on August 11, 2018.  The new term for the Pierce Mills Project is from February 6, 2017 through February 5, 2025.

12 juillet 2018 : The Low Impact Hydropower Institute (LIHI) preliminarily approved the Pierce Mills Hydroelectric Project for a new 8-year term of Low Impact Certification, having earned a PLUS Standard in the Recreation Criteria. This decision is preliminary pending the 30-day appeal window. Only those who commented in the initial application during the 60-day comment period are eligible to file an appeal. Such appeal needs to include an explanation as to how the projects do not meet the LIHI criteria. Appeal requests can be submitted by email to commentaires@lowimpacthydro.org with “Pierce Mills Hydroelectric Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Ave, Suite 2, Lexington, MA 02420. All requests will be posted to the website and the applicant will have an opportunity to respond and any response will also be posted. Les demandes doivent être reçues avant 17 heures, heure de l’Est, le 11 août 2018.  The full application and reviewer’s report are available below. If no appeal requests are received and the decision becomes final, the new term for the Pierce Mills Project will be February 6, 2017 through February 5, 2025.

11 juin 2018 : The Pierce Mills certification term has been extended again to September 30, 2018.

3 avril 2018 : The Pierce Mills certification term has been extended again to June 30, 2018.

28 novembre 2017 : The Pierce Mills certification term has been extended to March 31, 2018.

30 décembre 2016 : The Low Impact Hydropower Institute has received a complete application for a new term of Low Impact Certification for the Pierce Mills Hydroelectric project. The application materials can be found in the Files section below. LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Pierce Mills project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook released in March 2016.  Please review the program and criteria in LIHI’s revised Manuel and then review the Project’s 2016 application materials posted below. Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc.) will be most helpful, but all comments will be considered.  Comments may be submitted to the Institute by e-mail at commentaires@lowimpacthydro.org with “Pierce Mills Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, PO Box 194, Harrington Park, New Jersey 07640.  Les commentaires doivent être reçus à l'Institut au plus tard à 17 heures, heure de l'Est, le 4 mars 2017. à prendre en considération. Tous les commentaires seront publiés sur le site Web et le candidat aura la possibilité d'y répondre. Toute réponse sera également publiée.

16 décembre 2016 : The Pierce Mills Hydroelectric project has been granted an extension of the current certificate term. The new expiration date is May 6, 2017. See extension letter for explanation below.

9 septembre 2012 : The Pierce Mills project has been certified as low impact for a five year term, effective February 6, 2012 and expiring February 6, 2017.

6 avril 2012 : La période de commentaires publics sur la demande est terminée.

6 février 2012 : The Central Vermont Public Service Corporation has submitted an application for the certification of the Pierce Mills project. Public comment period on application has opened.

Dossiers de certification

Recertification 2017

Certification 2012

Documents clés